Where Do Flies Come From in Winter?

A close up image of fruit fly in Michigan Home

Having flies in your home is never fun, but during the winter it’s downright intolerable. After everything else you have to put up with, you don’t even get a break from pests? Unfortunately, flies are surprisingly common indoor pests during the winter. They might be around even if you can’t see them!

Winter flies may seem inexplicable, but, as always, there’s a pretty straightforward reason they’re in your home. Learning why your flies are around and what they want will help you make sure they can’t get it. Here’s all the info you should know about flies in winter, including how to keep them out.

How do flies survive winter?

There are hundreds of thousands of common fly species, and they deal with winter in all kinds of ways. “Filth” flies like blow flies, fruit flies, and phorid flies tend to live in and around garbage all year. During the winter, they simply nestle into garbage in sheltered areas and hunker down to preserve heat.

Other flies, such as face and cluster flies, lay eggs in warm areas during the fall. The flies laying the eggs dies of natural causes, but their offspring hatch all winter. Once the offspring are inside, they can continue reproducing, laying eggs, and hatching. Larger flies, like cluster flies, may also enter the state of diapause to preserve energy and body heat.

What are the flies inside my home?

The flies most likely to bother you in your home this winter are cluster flies, fruit flies, or house flies. Fruit flies and cluster flies are particularly common in Michigan, even during the winter. These flies are easy to tell apart: fruit flies are tiny, lightly-colored flies with big red eyes. Cluster flies are big, stocky flies with dark coloration.

Unsurprisingly, fruit flies are most common around your kitchen. They seek out warm, moist places where they can access food. Adult fruit flies lay eggs in rotting fruit and plant material. They may live in and around your garbage or drain. Cluster flies are common around windows, attics, and basements. They look for warm, secluded places where they can huddle together and enter diapause. Cluster flies occasionally re-emerge on warm days to regain heat and energy.

How do flies get inside my home?

Cluster flies work their way into homes starting in late summer and fall. They cluster together in large groups on the sides of walls to soak up sun and stay warm. As temperatures cool, the flies look for cracks and gaps they can use to stay out of the wind. Often, these cracks may lead them into your home, either behind the walls or in attics and basements. Common access points include cracks under baseboard, windows or door trim, and around fans, lights, or utilities.

Fruit flies may infiltrate your home by hiding inside grocery bags or other transported food materials. Fruit fly eggs are tiny and very difficult to see. If you accidentally bring a couple eggs indoors, those eggs may hatch and grow into an infestation. Adult fruit flies can also sense rotting or fermenting material and follow it back to your home. They may lay their eggs around your garbage or other areas where they can find rotting food.

What do flies want?

Without warm, secluded shelter, flies can’t survive freezing temperatures. Most common flies can’t hibernate, either, which means they need a shelter where they can access food. If you have flies, it means your home provides both of these things. Cluster flies look for warm, hidden areas where they can remain dormant for long periods. They won’t eat much, reproduce, or cause any real damage. The only time you may see them is during warm days, when they may emerge.

Fruit flies might be more annoying. They will eat, reproduce, and infest food supplies. Fruit flies attach themselves to any fermenting or rotting food–not just fruit. They’ll work their way into the rotting food to lay eggs and feed continuously. Like cluster flies, they need their food sources to be in warm places to survive. Fruit fly eggs will also die if exposed to freezing temperatures, so fruit flies have several incentives to get inside.

How can I get rid of flies?

Cluster flies are difficult to control in winter, because they may already be hiding in your walls. If you try sealing their access points now, you may trap the flies in your walls. That could create a mess and attract other, even less pleasant pests. When spring comes, cluster flies will typically leave your home to warm up outside. Until then, we recommend swatting or vacuuming the flies you encounter and leaving the rest alone.

Getting rid of fruit flies means wiping out their food and shelter sources. Look for any sources of rotting or fermenting food inside your home. Clear and clean out each of your garbage bins. Sanitize the places where you keep your garbage. Seal off possible access points around food, such as window frames in your kitchen or dining room. Fruit flies can squeeze through the smallest of gaps, so be thorough! Make sure you check around utility lines like pipes and electrical, too.‌

The good news is, flies aren’t really a big deal. None of the common flies that get in your home can hurt you or your stuff. At worst, you should consider them an annoyance. The bad news is, even if they’re “just” an annoyance, they’re still… annoying.

Luckily, you don’t have to deal with your flies. When you decide enough is enough, just give Griffin Pest Solutions a call. We’ll wipe out your flies so you can get back to enjoying (or at least tolerating) your winter in peace.

 

How Long Do Flies Live?

House fly perched on a plant stalk

How long a fly lives depends on its species and the temperature of its environment. In warm, humid environments with plentiful food, flies could live as few as 15 days. In cool, dry environments, fly development tends to take longer.

The faster flies grow, the faster they lay eggs. The faster they lay eggs, the more flies they produce! There are four common flies in Michigan: house flies, fruit flies, cluster flies, and phorid flies. Here’s how to figure out which fly you have and what to do about them:

Which flies do I have?

House flies

House fly

House flies (Musca domestica) are the most common fly infesting most homes. These flies are ⅛ to ¼” long, with grey bodies, red eyes, and four dark stripes. 

Female house flies lay eggs directly inside organic matter whenever possible. Inside your home, you’ll probably find these flies around trash bags, dumpsters, or dirty water. House flies make a distinctive buzzing noise when flying. 

Fruit flies

Fruit flies (Drosphila melanogaster) are around ⅛” long, tan, and have large red eyes. They lay their eggs in the moist film that develops on food and beverages as they ferment. 

Inside, you’ll find them near fruit, vegetables, garbage, and water. They’re especially common in kitchens, garbage disposals, open bottles and cans, and around mops and cleaning rags. 

Cluster flies

Cluster flies

Cluster flies (Pollenia rudis) look similar to house flies, but they’re slightly larger. Adult cluster flies are dull-grey with black markings. They also have yellow hairs on their thorax, which made give them a golden sheen. 

Cluster flies bury their eggs in the soil so larvae can feed on earthworms. You may see them clustered around your windows and doors, especially during the fall.

Phorid flies

Phorid flies

Phorid flies (Phoridae) resemble fruit flies, but they have long legs and lack the fruit flies’ red eyes. They’re about ⅛” long and translucent tan. Unlike other flies on this list, Phorid flies are not particularly competent fliers. 

They travel mostly by “scuttling” along surfaces. They feed and nest on decaying organic matter and stagnant, dirty water. They’re especially common around plumbing leaks.

How long do flies live?

House flies

In warm conditions, house flies complete their developmental cycles in as few as seven to ten days. During that time, house flies undergo complete metamorphosis with egg, larval, maggot, pupal, and adult stages. Adults usually live 15 to 25 days, but they could live for up to two months. House flies can reproduce immediately upon reaching adulthood and a single female fly can produce up to 3,000 eggs.

Fruit flies

In optimal conditions, fruit flies can advance from egg to adulthood in only eight to ten or ten to twelve days. They undergo embryo, larva, and pupal stages before reaching adulthood. Adults usually live around 30 additional days after metamorphosis. They reproduce immediately after reaching adulthood, and females can lay eggs 24 hours after mating. Each female fly can lay up to 500 eggs in her lifetime.

Cluster flies

Cluster fly development takes between 27 to 39 days. These flies go through egg, larvae, pupal, and adult stages. Adults lay eggs in the soil. Hatched larvae develop in earthworms. Flies don’t appear above ground until they’re fully developed. Adult cluster flies live longer than most flies and may overwinter in homes. Some cluster flies may live for up to one year. 

Phorid flies

A Phorid flies’ complete life cycle could take only fourteen days under optimal conditions. A single female phorid fly can lay up to 500 eggs in her lifetime. These eggs hatch within 24 hours. The resulting larvae feed for 8 to 16 days and then pupate into adults quickly. Flies can reproduce and restart the cycle as soon as they reach adulthood.

House flies swarming on a rotting onion in a garbage can

How do I keep these flies out of my home?

Flies are attracted to decaying organic material. House flies, fruit flies, and phorid flies seek out fermenting liquids and rotting food. Cluster flies live near rotting logs and stumps or dying weeds and grass that attract earthworms. Rinse out containers before throwing them away. Keep garbage and recycling in sealed plastic bags. Take out your garbage and recycling every night. Clean out your garbage cans and dumpsters frequently.  

Most the flies on this list are also attracted to moisture and humidity, especially near food. Flies are great at finding and exploiting plumbing leaks, condensation, and other sources of excess moisture. Look for leaks, condensation, dripping fixtures, and run-off in your kitchen, basement, and attic. Fix leaks, seal drafts with caulk, and clean up puddles and other water sources. Clean dirty drains and other sources of food or water back up, inside and outside.

 

As flies establish themselves, they’ll lay eggs, spread out, and entrench themselves in your home. Unfortunately, however, it can also be difficult to stop a fly infestation before it’s bad. Especially if they’re reproducing this quickly! Luckily, even if flies have established themselves in your home, you don’t have to put up with it.

If you have a fly problem, give Griffin Pest Solutions a call any time. Our experts will identify your fly, find its nests, wipe it out, and keep it from getting in again.

What Are the Flies in my Kitchen?

Fly attracted to food in kitchen

Easily the most common pest problem people deal with every day are flies in their kitchen. It makes sense: kitchens and other food storage areas naturally tend to create ideal fly infestation conditions. There are even all kinds of different common flies, and they’re all looking for something a little different. The trick to keeping flies away is figuring out what that “something” is and making sure they can’t get it.

Start by figuring out which kind of fly is bothering you. Chances are, it’s one of the four particularly pernicious pantry pests we’ve listed below. Once you’ve identified your nemesis, follow the steps below to deprive them of what they want. Don’t give up; a fly-free future is possible! Here’s how to keep four of the most common kitchen flies from bothering you anymore:

House fly

House fliesHouse flies are dark grey flies with four black stripes on their slightly hairy thoraxes. They’re around ⅛ to ¼” long and round or oval-shaped. The easiest way to identify a house fly is to look for their prominent red eyes. Usually, you’ll notice a house fly infestation when you see one of the flies near your garbage or food. You may also find small cream-colored eggs or larvae laid on food material.   

House flies are a problem because they transmit hundreds of pathogens via their saliva and waste. They also soil food products by laying eggs inside of them. Fruit flies are naturally attracted to water, sugar, broth, and soluble food stuff, which they feed on and lay eggs in. The best way to prevent house flies is to make these breeding sites inaccessible. Keep garbage sealed and dispose of it before it begins to rot. Rinse out bottles and cans before you throw them away. Store food like grains and pasta in sealed plastic containers.

Blowfly

blowfliesBlowflies (or bottle flies) are small, round flies that are metallic green, blue, or copper-colored. Their metallic-looking bodies are slightly iridescent and make them relatively easy to spot. They’re usually only around ¼ to ½” long. Blowflies congregate on dead, decaying, or rotting things in great numbers. They tend to be particularly noticeable outside during the summer. If you have them inside, they’re probably flying around either your garbage or some other source of rotting material.

Like house flies, blow flies are a problem primarily because they transmit diseases. Blowflies also reproduce astonishingly quickly. A large number of flies can inhabit a food source in a short period of time. When you have a blowfly problem, the first thing you should check is your garbage. Dispose of all your garbage and rinse out your cans and dumpsters. Look for and remove any sources of decaying organic material such as pet feces or fertilizer.

Fruit fly

Fruit fliesFruit flies or vinegar flies are tiny (⅛” long), very light tan flies with almost translucent bodies. Like house flies, their prominent, bright red flies are their most distinguishing feature. Fruit flies are attracted to any organic material that’s ripe, fermenting, or otherwise moist. They reproduce and lay eggs in any thin film of moisture on top of fermenting material. A single female fruit fly can lay 500 eggs. These flies have extremely short life spans and reproduce extremely quickly.

Fruit flies are primarily considered nuisance pests, but like other flies, they can also contaminate food sources with pathogens. Any food that could produce condensation could attract fruit flies and foster fruit fly growth. Pay close attention to where you’re throwing away food, especially fruits and vegetables. Even small sources of moisture like spilled fruit juice could attract literally thousands of fruit flies. Dispose of any overripe or rotting food regularly, and rinse out your garbage cans once a month.

Cluster fly

Cluster fliesCluster flies like the common cluster fly (Pollenia rudis) usually enter homes during the fall. They look very similar to common house flies, except they have patches of bright yellow hair under their wings. During spring and summer, they reproduce and lay eggs in the soil. Cluster flies produce three to four generations in a mating season. During fall, adult cluster flies attempt to enter enclosed and protected areas in order to survive winter.

Cluster flies are largely considered nuisance pests, similar to other overwintering nuisance pests such as stink bugs. They don’t damage your home or transmit diseases. Their bodies or waste may attract other pests to the areas they inhabit, however. The best way to keep cluster flies out of your home is to block their common entry points. Seal cracks around windows, doors, thresholds, and utility lines. Repair or replace damaged screens. Patch up cracks in chimneys or roofing shingles.

 

If you feel like you’ve tried everything and you still have a fly problem, don’t despair. There’s a reason why flies continue to be the most common pest problem in the US. The frustrating little bugs are very good at getting theirs. Luckily, we’re even better at stopping them.

If you decide you need some help dealing with your kitchen foes, give Griffin a call any time. We have everything we need to make your kitchen fly-free and keep it that way. Your fly-free future still awaits! All you have to do is call now.