Tag Archives: mosquitoes

Bag of water hanging from ceiling

15 mosquito-control strategies and devices that don’t work

Health officials love to remind people to use DEET and other CDC-approved repellents, but they tend to shy away from telling the public what doesn’t work. As a result, millions of people adopt ineffective techniques and gimmicky devices. These people are not only subjecting themselves to annoying mosquito bites, they are increasing the likelihood that family members will contract West Nile virus disease, Zika virus disease, eastern equine encephalitis, and other mosquito-borne diseases. So I thought I’d make a list of the top myths and scams just in case skeptical people are Googling.

1. Mosquito-repelling plants

Despite the claims of thousands of posts on Facebook and Pinterest, there are no plants that, when planted around your yard, repel mosquitoes. And, just to be clear, the plant marketed as “mosquito plant” does not repel mosquitoes. I know this is deeply upsetting news to many plant fans. I’m just the messenger.

2. Ultrasonic devices and apps

None of these have been found to work (details). It’s too bad. It would be really cool if they did. The FTC has taken some companies to court. There is, however, a device called The Mosquito that is effective at repelling teenagers.

3. Bags of water suspended from ceiling

This belief is common in Mexico, Central America, Spain, and certain pockets in the U.S. south. It’s a variation of the equally-ineffective tradition of hanging bags of water to repel house flies. Some people insist that you have to add coins (and just the right number).

4. Listerine

Nope — even when mixed with other ingredients like beer and epsom salts, spraying Listerine around your yard won’t repel mosquitoes. Just another internet rumor started by somebody with too much free time.

5. Citronella candles

Citronella candles only seem to work if you surround yourself with a lot of them, ideally in a protected area so that wind doesn’t dissipate the smoke. Similarly, Tiki torches that burn citronella-laced oil are ineffective. They smell great, though. The pleasant smell most likely contributes to the strong placebo effect. People absolutely believe they work even though they do not.

6. Bounce dryer sheets

Per one study fungus gnats (which don’t bite) were mildly repelled by dryer sheets. I’d wager these sheets might actually be attractive to mosquitoes (some species home in on perfumes).

7. Wrist bands with natural oils

At best, wrist bands will reduce the number of mosquito bites on your wrist. But they will not emit enough volatile compounds to shield the rest of you. NB: currently there are no wristbands that contain DEET or other CDC-approved repellent. Details.

8. Stickers laced with natural oils

Stickers only prevent mosquitoes from biting the flesh directly underneath the sticker. You’d need an awful lot of stickers for full protection. If you can rock that look, I say go for it. Note, same conclusion for the stickers that claim to infuse your bloodstream with B1.

9. Garlic

Eating garlic does not deter mosquitoes. Just other people.

10. Vitamin B1, B6, or B12 pills

Nope, nope, and nope. Details. More details.

11. Mozi-Q pills

Just another scam. Details.

12. Bug Zappers

These devices are adored by people because they make a satisfying crackle when an insect meets its end. Indeed, people who own these seem to delight in the attention these things get when friends come over in the evening. But if you dump all the carcasses on a table and sort them (good family fun), you’ll find that only a small fraction of the victims will be mosquitoes. In one study, 0.22% were mosquitoes. Mostly you’ve just electrocuted thousands of small, defenseless moths and night-active beetles. That’s a lot of bad karma. More details.

13. Dynatraps

These don’t appear to work. If you’re still on the fence read some of the many 1-star reviews on Amazon.

14. Spartan Mosquito Eradicators and Sock-It Skeeters

These are a commercial manifestations of the “DIY mosquito killer using soda bottle, yeast, and sugar” that has gone viral on Facebook and YouTube. Like the homemade version, these devices are really good at attracting and breeding fruit flies ( (they lay eggs!), but nothing else. They do not kill mosquitoes. Both devices are made by AC2T, Inc., a Mississippi company. More details.

15. Bats and birds

Sadly, it’s a myth that constructing a bat or bird hotel in your backyard will eliminate your mosquito problem. Bats and birds will certainly eat mosquitoes under some circumstances (e.g., when they are caged with nothing else) but under natural conditions they prefer to eat larger insects. You should still construct bird and bat houses, though. Details.

More information

If you have questions, email me.

Spartan Mosquito Eradicator (review)

Spartan Mosquito Eradicators are selling like hotcakes around the country so I bought two and thought I’d share some thoughts. The devices are just black tubes filled with water, sucrose, salt, and yeast that you hang in your yard. Per the company, mosquitoes are lured to the devices by the CO2 and heat produced by the yeast, crawl inside (through holes in the cap), drink the liquid, crawl back out, then eventually die when their guts rupture.

Spartan Mosquito Eradicator

How the device is supposed to work

The device is supposed to be an “attractive toxic sugar bait” (ATSB), an idea that is over 60-years old. ATSBs are increasingly viewed as a great alternative to spraying because they can be deployed cheaply and, if properly designed, limit the death of other insects. Here’s a nice summary of how they work (also see review by Fiorenzano et al. 2017). The Gates Foundation, in particular, is pushing the use of ATSB devices. The version that Spartan Mosquito makes resembles designs that are rather easy to make at home (e.g.), but incorporates yeast (as per this viral DIY trap from China) as a way to generate carbon dioxide. The inventor argues that the device works because it is designed to take advantage of the following facts:

  1. Mosquitoes are attracted to contrasting colors.
  2. Mosquitoes are attracted by CO2.
  3. Mosquitoes are attracted to heat.
  4. Mosquitoes regularly ingest carbohydrates from decaying (fermenting) fruit and nectar, and several studies have shown that mosquitoes are attracted to artificial solutions of sucrose and yeast (Oli et al. 2005, Smallegange et al. 2010, Sukumaran et al. 2015, Dhanique et al. 2017).
  5. Mosquitoes can crawl through holes.

Did they work?

No. I didn’t notice a drop in the number of mosquitoes in my yard. My mosquitoes are largely Asian tiger mosquitoes (Aedes albopictus) and several Culex species. I spend a lot of time outside so I would be in a position to know whether there was a reduction in mosquitoes. The devices simply didn’t work.

Why didn’t they work?

In my opinion, there are four reasons why the Spartan Mosquito Eradicator is unlikely to kill a single mosquito unless it falls from the tree and lands on one.

First, I don’t think the concoction inside the device is attracting mosquitoes. If it were, I would expect to see mosquitoes congregating around the device. I didn’t see a single mosquito, ever. As for reasons why the fermenting liquid isn’t attractive, it might be because the yeast runs out of sucrose in less than ten days (probably just two), so it’s just not producing enough carbon dioxide to fool mosquitoes into thinking it’s a bird or mammal. I’d guess that even on day one there’s not enough CO2 produced by this device. Another reason it’s probably unattractive is that the tube smells like rotting insects after a few days, not a nice piece of fruit or nectar source — again, mosquitoes are probably not going to be fooled.

I find it revealing that the company doesn’t publish data on CO2 production of the devices. One of the owners, Chris Bonner, owns a carbon dioxide meter (he does testing for the EPA). If you are state pesticide regulator, this would be a simple test to run, even off season. Just don’t ask Bonner Analytical Labs to do it.

UPDATE: After almost a year of looking online, I’ve NEVER found a photograph of a deployed Spartan Mosquito Eradicator that shows a mosquito on or even near the device. Not even the company has such a photograph.

Second, the fermentation reactions inside the tube are not going to generate enough heat to make the device a thermal target for mosquitoes. Even if there was a mild temperature elevation on the first day (when there is plenty of sugar), that temperature increase will certainly not last for three months. Notably, the nowhere on the company’s website or marketing materials is there any documentation of a temperature increase. For a company that made $100 million in 2019, you’d think they could spring for a remote food thermometer. It’s just a lie. If you are state pesticide regulator, this would be a simple test to run, even off season.

Third, sodium chloride (table salt) is unlikely to be an effective poison. My pessimism is because adult mosquitoes have salt-sensitive taste receptors just like we do and thus are unlikely to drink a solution that is too salty. I was unable to find a single published article that suggests mosquitoes would drink salty sugar solutions. Similarly, I couldn’t find any literature that said mosquito guts would rupture when forced to imbibe sugar/salt/yeast solutions. Notably (yet again) Spartan Mosquito doesn’t cite a single article on its website or marketing materials in support of its claim. Indeed, when females take a blood meal they are, in effect, ingesting a high-sodium solution. They simply excrete the excess sodium in their urine.

Why, then, does the company use sodium chloride as the active ingredient, when even a quick internet search would reveal it is poor choice? It turns out that the company initially used boric acid as a poison. I’ve uncovered two types of evidence for this. One is that “orthoboric acid” (not sodium chloride) is listed in the patent application. Another is a a video of the inventor/co-owner (Jeremy Hirsch) describing the poison as “boron or borax” to the Hattiesburg (Mississippi) City Council in April 2017; he doesn’t mention a salt version. I think he first settled on borax (which is cheap and easy to find) because he likely read, sometime in 2015 or 2016, an article in the New York Times titled, “Brewing up double-edged delicacies for mosquitoes“. In one part of the article there’s a description of an experiment that used boric acid to control malaria-transmitting mosquitoes in Africa. I think this was the article because Mr Hirsch often mentions in interviews that he thought he could improve upon what the Gates Foundation was doing (described more fully in Müller et al. 2010).

My guess is that at some point Mr Hirsch was told by the EPA that he wouldn’t get approval for the borax version unless he had valid efficacy data. So he switched to sodium chloride, which made his device eligible for an exemption to FIFRA 25(b) regulations: this allowed him to sell it in almost every state without needing any efficacy data. I.e., the Spartan Mosquito Eradicator can be sold even if it doesn’t work. Plus salt is cheaper than boric acid so he could make a higher profit.

One curious part of the sodium chloride usage is how the company describes the mechanism of action: the mosquito gut “ruptures” in response to sharp crystals of sodium chloride. Here’s how the company describes it to a customer on Facebook:

Even if you could fool a mosquito into ingesting a saline solution, this mode of action is improbable. Sodium chloride is ridiculously soluble in water so you’d need to have an extremely high concentration for salt to crystalize out of a solution. A 1% solution isn’t going to crystalize. I’m guessing the advertising was initially crafted to describe how boric acid kills insects and they decided to keep the wording because it sounds dramatic and, they found, many Americans found it convincing.

As an aside, just in case an EPA regulator chances upon this post, listing sodium chloride as the active ingredient is a violation of the 25(b) exemption granted to this device. I.e., the company has zero data showing that sodium chloride is killing mosquitos so salt cannot be listed as an active ingredient. Moreover, Spartan Mosquito admits that salt is not the active ingredient when it says that mosquito’s guts are ruptured by the yeast’s CO2 emissions. Here’s the Jeremy Hirsch’s own wording (see video): “When they go in and they consume the material basically the material with the yeast and the sugar is constantly producing CO2 and mosquitoes have no ability to expel excess gas.” Therefore, the company has misled the EPA as well as dozens of state regulators. I personally cannot understand how the Mississippi Bureau of Plant Industry ever allowed this sham of a product to be OK’d for sale in the first place. Truly a mystery.

Sodium chloride is the active ingredient.

Fourth, the holes in the cap are too small (5/32″) to allow mosquitoes to enter, at least with regard to mosquitoes in search of rotting fruit. There’s not a huge literature on what size holes mosquitoes can crawl through, but Dickerson et al. (2018) found that only 1 out of 100 female Aedes aegypti mosquitoes went through an 8-mm hole after 1 hour when presented with a host. Although a hungry female mosquito might squeeze itself through a small hole in search of a warm mammal (Bidlingmayer 1959), I doubt that they would do the same merely for some rotting sugar water. Or certainly not at a frequency that control a population of mosquitoes.

Spartan Mosquito Eradicator cap with holes.

Here’s a video of the device in action (inside an aquarium filled with hundreds of mosquitoes). Below is a screen grab of the video:

A Spartan Mosquito Eradicator inside an aquarium with hundreds of dying mosquitoes.
Frame grab from a time-lapse video of mosquitoes dying inside an aquarium in which a Spartan Mosquito Eradicator was placed.

My guess is that not even a single mosquito in the video entered the device — they just died over the course of several days from starvation and desiccation. It would be nice to know whether the company filmed it exactly as above (with holes hidden) or whether the company cropped out the holes after filming. The company wouldn’t respond when I asked. But even if the company shows a mosquito or two entering, if there were hundreds present in the aquarium, that’s an indication that the device isn’t going to work outside. I.e., if a yard has, say, 10,000 mosquitoes, having a dozen or so visit the device is not going to kill enough to be noticeable. And, as mentioned above, it’s unlikely that those rare mosquitoes entering the device are actually drinking the fluid (that would have to be demonstrated with an experiment).

I think a fundamental problem of the Spartan Mosquito Eradicator is that in a typical yard mosquitoes have plenty of nectar sources already, and perhaps also plenty of fruit. So even if mosquitoes could be coerced to enter small holes under laboratory conditions of starvation, they are simply not going to do that in the real world. For an experiment that underscores this issue, please see Beier et al. 2012.

Why do people buy them?

People buy Spartan Mosquito Eradicators for the same reason that people bought snake oil — they believed the marketing. And people become repeat buyers for the same reason people kept going back for more and more bottles of snake oil — people convince themselves that the device actually worked when in fact they do not. In fact, many avid fans refer to themselves as “believers”, acknowledging that most other people figure out that mosquitoes are not killed by the devices.

It’s not just the truly gullible that become believers. Many people in the United States don’t realize that towns and counties spray insecticides regularly, which lowers mosquito populations to tolerable levels. Other people might just happen to have low mosquito counts in their yards for some other reason (e.g., very little rain prior to setting the devices out in yard). Both of these scenarios can lead a person to conclude, wrongly, that the devices they set up in a yard caused the low mosquito numbers. This is called an illusion of causality, a phenomenon that explains why people become believers in all sorts of strange things (dowsing rods, golf-ball finders, etc.). And then once a person decides the devices work, the power of confirmation bias will continue to reinforce that incorrect conclusion. At this point, no amount of evidence to the contrary is likely to change their belief. E.g., if a Believer in Spartan Mosquito Eradicator gets eaten alive by mosquitoes in her yard, she’ll concoct a reason that somehow removes the blame from the device.

Another category of believer is owners of stores that sell Spartan Mosquito Eradicators. These individuals get a percentage of sales so they are potentially biased, but in my experience speaking with them they seem 100% convinced that the claims on the package must be true (why would the company have mislead them!?). The proof, to them, is that people keep buying the devices (thousands, in some stores). My guess is that people who figure out that the devices are ineffective will just say to themselves, “Well, dang, I just wasted $19.95 but I’m not going to waste any time trying to return the darn thing. And I’m not going to bother the nice family at the store that sold it to me. They’ll just try to sell me a fresh box.”

Psychology might also reveal why Spartan Mosquito Eradicators get so many good reviews on Amazon (3.7-star average). It turns out that a delay between purchase time and review time tends to inflate reviews — people just relax their expectations. This might be a huge effect for Spartan Mosquito Eradicators because some people might let months elapse before they evaluate whether they think they worked. Still, everyone tempted to buy one should really read the 1-star reviews. They are brutal.

As a side note, I find it bizarre that true believers keep buying replacement packs every 90 days. If these people are convinced the devices work they could save a lot of money by just refilling the tubes with fresh ingredients: 2 1/2 tbsp sugar, 1 tsp salt, 1/8 tsp yeast, 1.7 cups warm water. The company is concerned about this scenario and has the following warning: “Spartan Mosquito Eradicators cannot be reused or refilled. Imagine a glass of orange juice sitting on your porch for 3 months. We don’t want people pouring tubes out on the ground and having a house pet consume the materials” (italics added). This is inane.

Deceptive and illegal advertising

The company makes lots of claims, but provides little reassurance that such claims are grounded by reality. Take, for example, the graph on the box that claims to show mosquito populations are all but eliminated in 90 days.

Graph of percentage mosquitoes eliminated over time by Spartan Mosquito Eradicators.
Graph of percentage mosquitoes eliminated over time. On its website this image is named, “Diagram-of-What_V3.jpg”.

A typical person is going to see this graph and assume that an actual experiment was done. Oddly, no details about this graph are ever given on the website or elsewhere. Who collected the data? Where was it done? When was it done? How was it done? I’ve talked to a lot of people about this graph and I think it shows the number of mosquitoes landing on the company owner’s arm on two different days during an event the company calls, “Case Study CSL4GOV-ZIKA”. Here’s a handout the company distributed (details below):

Spartan Mosquito Eradicator Case Study by Joseph Waits and MS State Etymologist
Photograph of handout describing a shady case study by Spartan Mosquito Eradicator staff.

The document says that a Lamar County official (Joseph Waits) and an etymologist [sic] from the Mississippi Department of Health conducted a study in late 2016. It is worded to imply that the Spartan Mosquito Eradicators deployed in the area eliminated 100% of mosquitoes and that the Mississippi State Department of Health participated and approved of the data. It turns out the reason the final mosquito count was zero was because the State of Mississippi completely nuked the neighborhood with insecticides (on multiple days). The word on the street is that MS Department of Health is was highly displeased about how the document above was worded (lawyers were deployed, in fact).

I’d also like to point out how the company ended the document: “To date, this is the most effective, longest-lasting Zika control response on record anywhere.” That’s a very bold claim. And is a violation of the 25(b) exemption granted to the device. I.e., Spartan Mosquito implies the product can protect against a human disease. The claim is also made online: “Purchase the Spartan Mosquito Bomb and fight the Zika virus!”

“Purchase the Spartan Mosquito Bomb and fight the Zika virus!”

The company makes bold efficacy claims, too. For example, it asserts that the Spartan Mosquito Eradicator is better at controlling mosquitoes than pyrethroid spray services, automatic pyrethroid foggers, bug zappers, citronella candles/torches, and DEET repellents. Legally, a company cannot make these comparisons without actual data. So these claims are illegal.

Another illegal claim is that the device is chemical free. That’s not true, of course, because all of the ingredients are chemicals (e.g., NaCl, H2O, C12H22O11). Here’s an ad from the company’s website.

Spartan Mosquito Eradicator "chemical-free" claim

The company even has a video in which viewers are told not to use mosquito repellents (screenshot below). That’s not good health advice. The company makes similar claims on its website and on Amazon (“they can be potentially harmful“).

Spartan Mosquito Eradicator repellent dangerous

The government also frowns on using images of pregnant women, children, and pets to visually imply that a pesticide device is safe. Here’s an image on the box showing a pregnant woman, a child, and a pet:

Photograph on box showing pregnant woman and her family.

It’s not just the company that spreads false, unsubstantiated health claims. Its affiliates and distributors do, too. Here’s a typical post from the primary distributor, WDG Holdings, LLC.

Facebook post by WDG Holdings, LLC telling people buy Spartan Mosquito Eradicators to protect against eastern equine encephalitis.

The implication is that you should buy a Spartan Mosquito Eradicator to protect yourself and family from eastern equine encephalitis. It is illegal (under FIFRA guidelines) to claim such protection when there is no credible scientific backing. Yet this distributor’s Facebook posts are almost exclusively claims such as this. These posts help explain why so many customers (feed stores, hardware stores) of the distributor make identical claims.

Another example is a commercial by Hub City West Farm and Garden that was broadcast on Mississippi television in early 2019. It claims Spartan Mosquito Eradicators can protect your family and pets from mosquito-borne diseases. This claim, again, violates FIFRA requirements. And because the claim could result in people not protecting themselves with DEET, the claim is also morally wrong.

I am certain there are scientists out there who have tested these devices and found that they don’t work at all. E.g., it wouldn’t take long to see that mosquitoes aren’t particularly interested in going through the holes in the cap and that if they do they don’t drink the fluid inside. But anyone agreeing to test the devices for the company is prevented by a non-disclosure agreement (NDA) from disclosing the results. Note to those scientists: you can break an NDA if you think the company is engaging in illegal activities (such as false advertising or lying to the EPA).

Distasteful advertising

In addition to misleading consumers, Spartan Mosquito also produced a video ad featuring a father hitting his kids. Astonishing.

Deceptive customer support

The company has a carefully-crafted return policy: “Lights On Distributors [the distributor] does not honor returns due to improper use” (italics mine), and you have to return the product within 30 days. Per hundreds of interactions with 1-star reviewers on Amazon, the company always blames the user. Specifically, Mr Hirsch et al. will insist that the user failed to (1) “deploy” the devices early enough, (2) buy enough units for the size of the property, (3) place them in right spots, (4) place them at the right height in trees, or (5) wait long enough for devices to start working their magic. In some cases, customer is guilty of all of the above. I fully understand that some types of devices (airplanes, e.g.) don’t work if instructions are not followed, but I’d argue that Spartan Mosquito Eradicators is not such a device. The insistence that directions weren’t followed seems like a scheme to prevent people from returning the product and to immunize the company against scam complaints. Here’s a typical response (from Spartan Mosquito’s Facebook page):

If a buyer persists in claiming the devices simply don’t work, the company will ask the customer to call a “Deployment Specialist”, somebody who will call up your street address on a Google satellite map and tell you where you should put the devices (after you buy more). Sometimes the representative (Mr Hirsch himself, perhaps) will even inform the customers that it is really hard to educate the common person on the complex task of deploying the devices, all while referring to the customer as, “Sir” and “Ma’am” (which conveys politeness and annoyance at the same time). These tactics are not just patronizing, they are dishonest. Also, having a stranger examine your property on Google maps is creepy, especially if the interaction is done under duress.

Effects on wildlife

Although Spartan Mosquito Eradicators don’t eradicate mosquitoes, they do seem effective at killing non-target arthropods that are attracted to sugar and yeast. Below are photographs and IDs of the some of victims I’ve found inside.

Not surprisingly, after several weeks the liquid inside becomes a bubbling, charnel pit. And some of the visitors clearly lay eggs before they die because you can find larvae writhing around (video below). Some of these larvae are spotted-winged Drosophila (Drosophila suzukii), a rather bad economic pest. If you live near an orchard or berry farm, you most definitely should find that alarming.

Spartan Mosquito Eradicators also attract a lot of insects that are too large to fit through the holes. Two examples are below. I’ve heard they attract squirrels, too, which could be attracted to the sugar but might also enjoy eating the dead insects (they give off a rather pungent odor).

Are “Sock-It Skeeters” any better?

Sock-It Skeeters are cheaper versions of the Spartan Mosquito Eradicator. The prototype is pictured below, followed by the version that is in stores now.

What can be done?

I didn’t just write this post to satisfy geeky people’s curiosity. I think this company should be stopped and its assets frozen so that a class-action lawsuit can return the money to swindled customers. Its products put people at risk of contracting mosquito-borne diseases, and this consequence will be especially horrifying if they are allowed to sell in countries where such diseases are orders of magnitude more common. So if you have made it this far in my long post, please consider helping me shut down Spartan Mosquito.

By the way, here are photographs of the owners, Jeremy Hirsch (president) and Chris Bonner (vice-president).

Updates

  • In November 2019, Indiana, issued a “stop-sell” order on Spartan Mosquito Eradicators, citing (1) false and misleading advertising claims made by the company, (2) health claims made by the company and its affiliates, and (3) complete absence of trustworthy efficacy data. The state joins Connecticut, Idaho, New Mexico, South Dakota, and D.C. as places where the device may not be legally sold.
  • Multiple states have informed me that they are conducting investigations into both the Spartan Mosquito Eradicator and the Sock-It Skeeter.
  • I’m not allowed to reveal details, but the Environmental Protection Agency is conducting two separate investigations into Spartan Mosquito. These investigations may make the various state investigations unnecessary.
  • There is also an investigator for a consumer advocacy organization looking into the matter. Hopefully this organization will hook up with the Federal Trade Commission and perhaps some state attorneys general, as it often does.
  • There’s an insect-focused professional society that is considering making a public statement about the devices (i.e., that there is no evidence that they work).
  • Both Amazon and Lowe’s are reevaluating whether to allow the sale of Spartan Mosquito Eradicators (currently, neither company sells the Sock-It Skeeter).

If I’ve missed anything, please drop me a line.

Eliminate mosquitoes by eliminating stagnant water

The most effective, cheapest way to control mosquitoes is to eliminate the standing water that larvae need to develop. A dry yard doesn’t have mosquitoes. It’s really that simple. Below is a list of objects to get rid of or dump regularly. Please share with your neighbors.

1. Gutters

This is at the top of the list because almost all houses have gutters and almost all homeowners hate to clean them out. Check for blocked gutters weekly if you have a lot of trees nearby. If gutter status is hard to see, buy a drone to facilitate inspections. If you can’t afford a drone just get an extra-long, telescoping selfie stick for your smartphone.

2. Flexible downspout extenders

Flexible downspout extenders are perfect for mosquito larvae — the ridges hold water and trap organic matter, the black absorbs heat from sunlight (thus speeding development), and female mosquitoes of several species just adore ovipositing inside plastic objects. They are especially bad if nestled in shrubs and ground cover. Note that they hold water even if they are sloped downward. Get rid of them. All of them.

3. Tarps

If you leave a tarp in your yard, you’ve created lots of nooks in which water and debris will accumulate. I frequently see tarps covering soggy logs that owners seem to have no real intention of ever splitting into firewood. I think people view tarps as cloaks of invisibility, magically hiding loathsome to-do items from spouse.

4. Toys

Sandbox toys, sleds, wagons, and kiddie pools seem as if they were specifically designed to encourage mosquitoes. I.e., even when stored upside down they have nooks that collect enough rainwater to allow mosquito larvae to mature. Store them in the garage. If you think covering them with a tarp will work, please see #3.

5. Bird baths

Everyone should have a bird bath. But if you do, you need to either have a water bubbler/agitator (mosquitoes hate that) or you need to kill the larvae by adding granules of Bacillus thuringiensis var israelensis (abbreviated, Bti). Bti is extremely effective: you can add it a container that has thousands wriggling of larvae (see movie) and they will all be dead within hours. Just add it every two weeks and your bath will always be mosquito free. But don’t forget — make yourself a smartphone reminder or write on paper calendar.

Bird bath next to purple coneflowers

6. Trash and recycling bins

If you can’t store your trash and recycling containers under a roofed area, keep a lid on them. I found the ones below behind a local church. Tens of thousands of larvae within.

Recycling bins with stagnant water

7. Watering cans

Watering cans are rarely transparent so you can’t see the mosquito larvae inside, but they are present if you leave them around the yard when it’s been raining a lot. Store them empty, in garage.

8. Wheelbarrows

Just keep them propped up vertically so they don’t accumulate rain water. Or drill holes.

9. Rain barrels

Just put screening over the top. Or add Bti every other week. I don’t recommend adding mosquito-eating fish because they die when water level gets low (plus the fish suffer before dying).

10. Pot saucers

Pot saucers are unneeded outside so it’s easy to eliminate them. If you like them for decorative reasons you’ll need to add Bti regularly. It’s better to just get rid of them because you’ll eventually forget. You know you will.

Other places where mosquitoes larvae thrive

Below are photographs of stagnant water I’ve noticed around my town. On my list of photographs to add: bromeliad, pool cover, bottle cap.