Fly Swarms In My House

June 23, 2016

In: Flies

Are you finding groups of flies buzzing around on window ledges or in the corners of your home? If you are, it can be disturbing, especially if you think those are common house flies, Musca domestica. After all, house flies come into your home one at a time and drive you crazy, individually. It is quite another thing to have a group of flies, or a cluster if you will. We have good news for you. Those aren't house flies. Those are cluster flies. And, we can tell you all about them.

The first thing you need to know about cluster flies is that they are overwintering pests. You're likely seeing these flies because they were warming themselves on the sunny side of your house last fall and found their way in. They didn't come in because you have a nasty house or because you left some food sitting out. They just wanted to stay warm. Now, they are just trying to get back outside. That is why they are congregating on your window sills and crawling around on the interior of your windows.

Cluster flies, called Pollenia rudis, are definitely rude house guests, as the name "rudis" might suggest, but they don't mean to be. Unlike house flies, cluster flies don't actually prefer to be inside your home. These are not garbage eating flies. Cluster flies prefer to eat flower nectar and would rather spend their days laying eggs in the soil around your home rather than smacking their head against your windows. Why do they lay their eggs in soil? Because their larvae infect earthworms and use them as a food source as they grow. They will usually feed for about 22 days and then go into a pupae stage for another 11 days after that. So, in a little over a month, these flies can become even more flies warming themselves on the sunny side of your home and getting into your wall voids and attic spaces.

Can I just open the window? While this can definitely let a few flies out of your home, these insects are likely to keep emerging from your walls. And, although cluster flies aren't a danger to your family, they are definitely a nuisance.

There is good news. Cluster flies can be eradicated and prevented with pest control products. With proper education and experience, these invaders can be vanquished safely and thoroughly.

If you need assistance with a cluster fly problem in western Massachusetts or Hartford County, Connecticut, American Pest Solutions can help you out. With over 100 years of experience and the most advanced equipment available, you can trust our team to protect your home from any pest.