Are Cluster Flies Dangerous?

Cluster fly on a house plant.

There are many different species of flies found invading homes, and while each species has its own unique characteristics, they generally have one thing in common. Most will buzz annoyingly around your head and throughout your home making themselves a complete nuisance. Cluster flies are a species that commonly invade homes. Since they are a fairly common pest, we want to provide you with some helpful information about them, including whether or not they are simply a nuisance or if they are actually a dangerous pest to have in your home.

But before the burning question of whether cluster flies are dangerous or not is answered, let’s talk a bit about this species of fly and their unique characteristics. Cluster flies are often confused with house flies because they tend to look like a very big house fly; however, if you look more closely, you will see that they are lacking the metallic sheen that houseflies possess and have distinct stripes behind their head along with golden hairs on their thorax.

Cluster flies move in a lethargic manner and often enter homes and other structures in the fall and “cluster” together in large groups behind walls, in crawl spaces, and in attics where they will hibernate during the winter months. They may emerge confused on a warm sunny day and gather on window sills and in window corners, but once spring comes back around they will move around your home, buzzing loudly around your head trying to make their way back outside.

Now back to the original question. The answer is no, they are actually much less of a health hazard to people than the common house fly. Cluster flies don’t bite people and they do not lay their eggs on our food. Instead, they lay their eggs inside earthworms. After the larvae hatch from their egg, they feed on the earthworm. So while cluster flies are dangerous to earthworms, they really aren’t considered to be harmful to humans. With that being said, if cluster flies do find their way into your home, it is best to eliminate them as quickly as possible - because when push comes to shove, no species of fly makes a good houseguest.

Listed below are some easy steps that you can take around your home now to try and prevent cluster flies from entering.

  • Caulk spaces found around exterior windows and doors.
  • Seal cracks and crevices found in the foundation.
  • Make sure that screen windows and doors are completely intact.
  • Place secure screens over vent openings.
  • Fill in the spaces found around utility entrances.

If cluster flies do manage to sneak their way into your home, the best solution is to contact the pest control professionals at American Pest Solutions. Our professionals have experience treating cluster fly infestations and will be able to inspect your home and develop a treatment plan to quickly get rid of the infestation. If cluster flies make their way into your home, leave the fly control up to us. Give American Pest Solutions a call as soon as possible to learn more about our residential pest control services!