Picture this: it’s a beautiful nice warm sunny day, so you decide to bring your lunch outside to eat it on your patio. Only to be bombarded by flies. Picture this: it’s a beautiful nice warm sunny day, so you decide to bring your lunch outside to eat it on your patio. Only to be bombarded by flies. Ugh, there are only few things that are more annoying than a swarm of cluster flies on a warm day.

Cluster flies are unlike regular house flies in the fact that they are going to congregate in the first warm spot they find, and if they end up inside your house, they can create stains on your walls and curtains. Getting rid of them these pests as soon as you can is a must.

A Quick Overview

Cluster flies are sometimes called attic flies, and they’re a bit bigger than your normal house fly. They’re usually eight to ten millimeters in length, and they have grey-checked abdomens. The thorax of the adult has golden hairs all over it, and when they’re at rest, their wings tend to overlap. In comparison with your usual house fly, they move at a lazy pace, seeking out warmth wherever they can get it.

Cluster flies typically begin their life cycle in the late summer, though early fall is a prime breeding time as well. The eggs hatch after just a few days, and the larvae then head to the bodies of earthworms so they can feed on them, then molt and pupate. Development from egg to adult takes as few as 27 days.

The Potential For Damage

Cluster flies are more a nuisance than a damaging pest. They won’t actually hurt your home, but they can leave dark spots on your windows and walls. What’s more, though, is that (as their name indicates), they love to cluster together, so you’ll see them in fairly large groups inside or outside your home trying to get to that sunlight, which can create other pest management issues.

The Prevention Factor

It’s easier to prevent a problem with these pests than it is to deal with one after it’s arrived. The best way to keep them out of your house is to seal things carefully. Look for cracks around your windows and doors. You may also want to look at spaces between the utility pipes and your home. Seal up what you can with silicone or silicone-latex caulk. Replace window and door screens as soon as you notice a problem. You may want to inspect the exterior of your home just before breeding season if you’ve had trouble with these pests before.

Once these pests are inside, you’re going to want to consult a pest control specialist. Simply using the first off-the-shelf insecticide you see if they’re already inside your attic is a really poor choice. It will kill them, but it might also encourage the infestation of other pests like carpet beetles to feed on the dead carcasses, then you have an entirely different problem. Instead, contact someone who can help you deal with the current problem and keep it from happening again.