7 Places Mosquitoes Go During The Winter (And When They Return)

If you are anything like me, then you probably agree that mosquitoes suck! One of my favorite times of the year is late fall and early winter, when these pesky insects aren’t around to make me itch. However, you might wonder where all these mosquitoes go during winter.

During winter, adult mosquitoes will go into a hibernation-like state and hide somewhere secure, including under bark, inside hollow logs, crawlspaces, under tree roots, inside animal burrows, or even inside buildings. Mosquito eggs, on the other hand, are very hardy and will survive through winter.

Keep on reading to learn how mosquitoes choose their hiding spots, how they survive winter, and when they come back to pester everyone once again!

Where Do Mosquitoes Hide During The Winter?

Knowing where mosquitoes hide in the winter is important to keep their population down once spring comes.

Understanding Mosquito “Hibernation”

Understanding where mosquitoes go during the winter starts with understanding how mosquitoes survive the cold weather that winter brings. They are cold-blooded, meaning that they cannot produce heat in their body and rely on external heating to warm them up and provide energy.

This is part of the reasons are not so active when the weather cools off, below 50 degrees Fahrenheit most of their bodily functions no longer work and they are “turned off.” In many places where mosquitoes live, winters get much colder than 50 degrees and so they have to do something to survive this cold weather.

What mosquitoes do during the winter isn’t called hibernation, it is called diapause. Functionally similar to hibernation in a lot of ways, diapause is essentially suspended development due to external (usually negative) weather conditions. In diapause, imagine it’s like cyrogenisis in humans if we ever get that tech perfected!

HIBERNATION on the other hand is simply taking a long snooze for the winter. In diapause, the mosquito will stop all development where hibernating critters will function as normal, just slower.

Much like a bear, mosquitoes will eat as much food as they can before the cold weather comes in and get bulked up before entering diapause.

According to the University of Alaska Fairbanks Geophysical Institute, mosquitoes go through two biochemical processes to prepare for winter. The first replaces any water in its body with glycerol, which is a carbohydrate that freezes at a much lower temperature than water. The second is supercooling, where the mosquito will lower its body temperature without letting any liquids freeze.

Both these processes are vital to survival over winter for mosquitoes in combination with a secure place to hide with protection from the elements and any predators. Below are some of the most likely places a mosquito might choose to stay for winter.

Mosquitoes Are Likely To Hide In Tree Bark

Mosquitoes will call tree bark home year-round, using it for shelter during bad weather during warmer months, and will make tree bark a long-term home during winter. Tree bark is a very protective place for mosquitos that offers protection from the elements and insulation from the cold.

The trees themselves also provide some small amount of warmth as they soak up the sun and are insulated by their bark. This small amount of extra warmth can play a big part in the survival of mosquitoes in exceptionally cold environments.

Trees close to water are more likely to be used as a shelter during warmer months, and when they decide to hunker down for the winter. They are likely to stay in the same areas close to the water for when temperatures warm back up.

Year-round, you are most likely to find adult mosquitoes hiding in tree bark because it is very well protected and often available around different bodies of water.

Another advantage of tree bark is mosquitoes are far off the ground and protected from many opportunistic predators. Especially during winter conditions where food is tough, many animals will happily eat any mosquitos for a snack, and being off the ground decreases their chances of being found.

Logs Offer A Safe Haven From Winter Conditions For Mosquitoes

Fallen logs offer another safe place or mosquitoes to go during winter with some distinct advantages and disadvantages for them compared to living tree bark.

The bark on logs is just one of the many safe areas for mosquitoes as rotting logs offer many cracks and crevices as they naturally hallow out from the inside. As other insects such as ants and termites make their home in logs, there will be many small places for mosquitoes to hunker down during the winter.

Simply burrowing underneath the log offers a secure roof and some protection from the elements. Flipping over logs in winter, you’re likely to find a whole host of insects waiting for warmer days to come out of hiding and become a nuisance again.

Depending on the environment and the cover to choose from, fallen logs may be one of the most ideal locations for mosquitoes to spend winter. Sharing many similarities with what makes tree bark great for mosquitoes, along with extra places to hide, makes it a common place for adult mosquitoes to lie in wait.

Mosquitoes Might Be Indoors Along With You

While mosquitoes are well equipped with survival mechanisms to make it through winter in harsh conditions, they might opt for an easier winter destination instead.

Indoors might include a barn or shed where it is insulated and protected from the elements or inside heated homes. Both places are common for mosquitoes to hide out in winter because they offer much better protection than any places in nature.

If you live in an area where mosquitoes are particularly common, chances are they make their way inside somewhere close to your home to wait out the winter.

You can read more about what to do if you have mosquitoes in your home here!

Barn and sheds are especially suitable spots because they will get cold enough to trigger diapause and help mosquitoes survive all of winter, but warm enough that they will have no problems making it through the rough weather.

Heated barns also might be a great place for mosquitoes to develop and live almost normally, albeit entirely inside and with a tiny population. If you keep any livestock indoors, monitor any standing water during the winter as mosquitoes can make it inside and continue to reproduce.

Using a livestock-safe insect repellent such as Farnam’s 10330 X Insecticide or another permethrin-based repellent can help if you are finding a mosquito problem during the winter. Using a spray can help prevent any unnecessary discomfort or stress for wintering animals.

You also might find mosquitoes trying to call your home their own during winter, and this can be a problem for many people. Using a trap may be necessary to catch any stragglers who made it into your home. The Katchy Indoor Insect Trap offers a three-step trapping mechanism using UV light, a fan to suck them in, and a sticky trap to keep any from getting out.

As an added benefit, this trap will catch more than mosquitoes and will catch fruit flies, gnats, and no-see-ums, all of which can be a nuisance and gives this trap use year-round.

Mosquitoes in the home and other structures can be a common occurrence year-round but comes as a surprise during the dead of winter, but from the mosquito’s point of view, they found a great place to live.

Mosquitoes Might Spend Winter With Creepy Crawlies In The Crawlspace

Mosquitoes like warm spaces and crawlspaces offer this along with protection from the elements. Your crawlspace is likely not an area that you spend a lot of time in, but mosquitos and other bugs might be down there.

Mosquitos make homes in crawlspaces more often than you might think. However, it should be limited to winter only.

Much like the other areas on this list, crawlspaces offer all the protection and extra warmth to keep mosquitoes protected and happy during winter and small spaces to hide from predators.

Mosquitoes in crawl spaces will probably go unnoticed all winter, but if you do have a problem with mosquitoes during winter and cannot find any in the rest of your house, then there may be bigger issues.

Mosquitoes need standing water to breed, and if you are having a problem with mosquitoes and believe it to be from your crawlspace, then this is a terrible sign. Standing water in crawlspaces might cause more pest infestations, mold, and damage to the foundation of the house.

If you do not feel comfortable crawling around in a crawlspace, as many people do not, then calling a professional might be the next step. A pest control expert will be able to help you identify and remedy any problems you might have.

Mosquitoes Might Be Unwanted Guests In Animal Burrows

Just like mosquitoes might make your home their shelter during winter, they might do the same to other animals. Both abandoned and active burrows might end up being used as mosquito real estate.

Animal burrows offer a lot of benefits for mosquitoes who are looking for cover from the snow and cold. Animal shelters are designed specifically for this purpose and make excellent cover for mosquitoes.

Protection from any precipitation and wind is a given because burrows offer almost 360-degree protection from outside forces. Animal shelters are designed to prevent any flooding that may occur as snow melts, which makes it easier for mosquitoes to fly away in the spring.

Animal burrows also offer the benefit of being underground where the temperature is higher than ambient temperature. In especially cold areas such as Alaska, this can make a vast difference in the survival of mosquitoes as every degree counts.

Mosquitoes may suffer and die off while hibernating at -15 degrees F, and many of their hiding spots will keep them above this temperature even in the coldest weather. Animal burrows especially benefit from being close to or under the frost line, which offers plenty of insulation.

Surviving in dens with other animals in them is even easier for mosquitos as they are plenty small enough to remain unseen and benefit from the additional warmth other animals provide. Any burrowing mammal makes an excellent resource for mosquitoes surviving the winter.

Some Mosquitoes Will Stay Beneath The Snow

In Northern climates, some mosquito species are very well adapted to surviving the cold and may not make it to a good hiding spot and instead rough it out in an open area under the snow.

While this is not the most common spot for mosquitoes to be during the winter, it happens and many mosquitoes will survive this way. Underneath the snow mosquitoes are protected and unlikely to get crushed in the stillness of winter.

Being underneath the snow and surviving the cold weather just goes to show how resilient mosquitoes can be. Their diapause lets them survive through very cold and difficult weather that most animals would not survive in.

Mosquito Eggs Will Survive More Than You Might Expect

While adult mosquitoes are well adapted to survive the winter, mosquito eggs are on a whole other level. Mosquito eggs also go through diapause, meaning that they cease all development during cold weather and resume when the weather warms up.

Mosquitoes lay their eggs in water as the eggs, larvae, and pupae all are aquatic stages of life. This means most mosquito eggs are laid in stagnant water somewhere and over winter, those eggs will remain there.

If those stagnant water sources dry up during winter, the eggs will survive for months even without water. In the spring, when the snow melts and rehydrates those eggs and temperatures continue to rise, the new mosquito larva will hatch and develop into the next generation of annoying bugs.

Mosquito eggs hold the bulk of the next year’s mosquitoes, and the adults that survive over winter represent only a fraction of the new population. Not all mosquito species have adults that can survive over a rough winter, but all the eggs can survive through some freezing weather.

Mosquito eggs are so tough that no matter how cold the weather gets in an area, they will continue to establish new populations in the spring over and over. While this is very impressive from a survival viewpoint, this is unfortunate for people because it means that mosquitoes will keep coming back.

When Do Mosquitoes Return After Winter?

Spring Brings Flowers, Birds, And… Mosquitoes 

After a long winter when all the snow is melting, flowers are blooming, and the weather is enjoyable can seem like a nice break from winter conditions. However, this new warmth will bring with it some challenges.

Mosquitoes will typically return in the spring when the weather is above 50F. Depending on which of the over 3000 species of mosquitoes are common in your area, they can be active in different temperatures so some may come out a bit colder or warmer but 50 degrees F is a good rule of thumb.

The National Library of Medicine published an article that examines when mosquitoes are most active, which is warm and humid weather without rain is the most likely time for mosquitoes to be out searching for food.

The most active temperature for mosquitoes is around 80F, which may take a few months into spring to reach those temperatures in some areas. As a result, you’ll notice mosquito populations growing as the weather gets warmer and becoming more and more of a nuisance.

Tips To Keep Mosquitoes At Bay Once They Come Back

While mosquitoes come out to feed, take some time to make preparations to keep them from feeding on you.

Now to summarize quickly –

Some ways to keep mosquitoes away, you can:

• Burn citronella candles, which are one of the oldest forms of mosquito repellent, and are both easy and effective.
• Plant lavender or use essential oils as another smell the mosquitoes can’t stand and will keep them away.
•  Rosemary is a powerful deterrent for mosquitoes and covers up a lot of the smells that mosquitoes rely on to find food sources. 

Check out this article about 9 scents that mosquitoes hate for more details on some easy ways to keep those pesky little buggers away. This article will go much more in-depth on these scents and others and is a great resource for fighting off mosquitoes.

If your area is heavily infested with mosquitoes and you can’t seem to keep them away, then it may be time to call a professional. Pest control experts will be equipped to find where the mosquitoes are breeding, determine the population density, and help you with the best course of action to limit these mosquito populations.

Many counties will also send out representatives to check water sources and decide if there is a course of action such as spraying a wide area is needed.

Mosquitoes are pests that can carry many diseases and cause health problems that can affect all people and are not a pest to be ignored. Even without the diseases they carry, nobody wants to deal with the itchy lumps that they leave as a parting gift.

If you want more ways to keep mosquitoes at bay, check out our list of ways to keep mosquitoes out of your house here!

Thank You For Reading!

We hope this article answered your questions about where mosquitoes go during the winter, and when to expect them to make a comeback!

Just as a recap, you can expect mosquitoes to be diapausing for the winter somewhere secure such as:

• Inside tree bark
• Under logs
• Indoors
• In a crawlspace 
• In another animal’s burrow
• Under the snow
• Eggs waiting to hatch
  

And you can expect to see them return once the weather improves and gets to 50 degrees, and stay around until winter returns.

References

Covell, G. (1955). Mosquito Bionomics. BMJ, 1(4922), 1138–1138.

Reisen, W. K., Cayan, D., Tyree, M., Barker, C. M., Eldridge, B., & Dettinger, M. (2008). Impact of climate variation on Mosquito Abundance in California. Journal of Vector Ecology, 33(1), 89–98.

Sota, T., Mogi, M., & Hayamizu, E. (1994). Habitat stability and the larval mosquito community in tree holes and other containers on a Temperate Island. Population Ecology, 36(1), 93–104.

Watanabe, K., Fukui, S., & Ohta, S. (2017, June 22). Population of the temperate mosquito, culex pipiens, decreases in response to habitat climatological changes in future. GeoHealth.