June 4, 2024

Where Do Flies Go In The Winter? Find Out Here

As temperatures drop and winter approaches, many insects adjust their behaviors to survive the colder months. Flies are not different! These pests also undergo their fair share of changes as winter sets in.

Understanding where flies go in winter is essential for homeowners and businesses alike, as it can help you manage and prevent infestations during the colder months. We’ll delve into the common fly species you may spot during the winter, either indoors or outdoors.

Where Do Flies Go In Winter?

Winter presents unique challenges for flies, forcing them to adapt their behavior to survive the harsh conditions. Here's a closer look at how flies behave during the colder months:


During winter, many fly species enter a state of diapause, or a period of suspended development and reduced metabolic activity. Diapause allows flies to conserve energy and withstand harsh conditions.

Changes in temperature and day length often trigger diapause. As temperatures drop and daylight hours decrease, flies receive signals to enter this hibernation period and prepare for the cold season.

Overwintering Sites

Finding suitable overwintering sites is crucial for flies in colder regions during winter.

Flies may seek refuge in indoor habitats, like attics or basements, where temperatures are more stable and protected from extreme weather conditions. These spaces provide ideal overwintering sites, offering insulation from the cold and protection from predators.

In outdoor environments, flies may seek shelter in natural features such as leaf litter, soil, and vegetation. These areas provide insulation from the cold and protection from predators, allowing flies to survive until conditions become more favorable.

Staying Place in Warmer Environments

Some fly species may remain active throughout the winter in regions with mild or temperate climates. These flies take advantage of favorable conditions to continue breeding and foraging for food.

Homeowners and businesses in warmer climates may still encounter fly infestations during winter, meaning you may need ongoing pest management services to control the pest populations.

Common Winter Fly Species

From seeking shelter indoors to adapting to changing environmental conditions, these flies try many strategies to survive during the winter.

House Flies

House flies (Musca domestica) may come indoors to escape the chilly outdoor conditions in winter. House flies may inhabit residential homes, commercial buildings, and agricultural facilities. Once inside, they may congregate in warm, sheltered areas like kitchens, bathrooms, and utility rooms.

House flies need steady access to food and moisture, which are abundant in indoor environments. To meet their nutritional needs, house flies feed on food scraps, garbage, and pet waste.

Leaky pipes, dripping faucets, and standing water are common moisture sources for these pests. By relying on these resources, flies can sustain themselves throughout winter and keep reproducing indoors.

Cluster Flies

Cluster flies (Pollenia spp.) are another common fly species that live indoors during the winter. Unlike house flies, cluster flies don’t sneak inside households or businesses during warmer temperatures. Instead, they stick around fields, forests, and grasslands.

However, these pests head indoors in droves to shelter in warm, covered areas whenever the temperature drops. Cluster flies can enter buildings through small cracks, gaps, or openings in windows, doors, and even along utility entrances. As evidenced by their name, you can often spot them congregating in clusters to conserve heat and energy.  

Preferred overwintering habitats for cluster flies include attics, wall voids, and other secluded areas within buildings. These sheltered spaces help the flies survive until the spring, providing insulation from the cold and protection from predators,

Fruit Flies

Fruit flies (Drosophila melanogaster) are resourceful and often find their way into our kitchens to find overripe fruit, fermenting food, and other tempting scraps. They’ll stick around if you have any of these in your kitchen—salad dressing, unsealed soy sauce, or glasses of fermented drinks.

But where do fruit flies go in the winter?

Fruit flies don’t disappear—they adjust. While winter weather doesn’t necessarily wipe out fruit fly populations, cold temperatures impact their development.

Some fruit fly larvae remain dormant during winter, conserving energy until warmer temperatures signal their awakening. Below 53°F (12°C), they stop developing altogether. However, adult fruit flies can “overwinter” when conditions become extreme.

Preventing and Managing Winter Fly Infestations

Whether you're dealing with house, cluster, or fruit flies, we have several strategies for eliminating and keeping these pests away!

Macro image of a black fly

Keep It Clean

Flies are attracted to food residues, spills, and organic matter, so clean up spills and crumbs from kitchen surfaces, floors, and appliances. Remember to keep dining areas tidy, too, and sweep up after meals.

Keep your garbage bins tightly sealed and empty indoor trash regularly. Flies flock to decaying organic matter that accumulates in trash cans, and an infestation can quickly spiral out of control if you leave old food sitting in your trash for too long!

Proper Food Storage

Flies are constantly on the lookout for food, but proper food storage can significantly reduce their attraction to your home.

Store perishable foods in your refrigerator, and avoid leaving fruits, vegetables, and other food items on your countertops. Put these items in airtight containers to prevent flies from accessing it. This includes pet food, which can also attract flies.

Seal Entry Points

Regularly inspect your home for cracks, gaps, and other potential entry points around windows, doors, and foundations. Use caulk or weatherstripping to seal openings that flies could use to enter your home. Add screens to your windows and doors and repair them often!

Professional Pest Control

If you're struggling with winter fly infestations, our professional pest control team can lend a hand. We'll conduct a thorough inspection to identify the source of your inspection and eliminate potential breeding sites.

For professional pest control services in Washington and Utah, contact us today!

Schedule Today!

Contact your local Zunex pest expert to schedule a treatment today!