Image by gowtham v from Pixabay
It’s the end of summer and things are getting cooler, but you notice on your window facing south that there are lots of flies collecting. It’s happened all of a sudden and you think maybe they are house flies. These flies are likely not your typical house flies, but are bigger and known as cluster flies. They are about 8 to 10 mm long and are dark grey with golden hairs on the upper body. Unlike house flies their wings overlap when they are at rest.
These slow-moving sluggish flies like to be around houses that are near large green spaces. Sometimes they can give off a sickly sweetish odor when they are disturbed. Cluster flies hibernate in the secluded areas of the house such as the attic and wall voids. They are very much a nuisance pest indoors and do not breed inside your home. They are not known to damage structures but they can leave tiny dots of excrement where they cluster. Adult cluster flies will start looking for a place to overwinter in the late summer and early fall. This is when sometimes they get into your home by accident. After sunning themselves during the day, they will looks for a warm place for the night.
Cluster flies are interesting insects that mostly stay outdoors, but just happen to enter your home seeking warmth to survive the winter or they may appear as they awaken in the spring as things warm up and they return to the outdoors. They typically lay eggs in soil, which hatch into larvae. These larvae search for earthworms living in the ground and the earthworm is parasitized by the larvae. The cluster fly larvae then feeds on the earthworm for about 20 days before entering the pupal state.
Cluster flies can gain access into your home through tiny cracks and crevices around the door and window frames. Make sure that all screens fit properly and weather strip your windows and doors. Fill any cracks with caulking around the doors, window frames and other gaps. If they have already made their way inside, you’ll want to vacuum them up. If you squish them they can release an odor and leave a stain, so even if they are a bit sluggish and easy to catch with a fly swatter you may want to use the vacuum instead. It’s best to clean up all of the dead ones you can find as you don’t want to attract other insects such as larder beetles. You can also use a flypaper or sticky trap to collect live ones.
If your infestation is too overwhelming, Absolute Pest Control can help rid the home of cluster flies. We have products that can be sprayed around the outside surfaces of the windows and doors to prevent entry. We also have products that can be utilized safely inside. Give us a call today at 403-238-7400 for more information and to see about having your home treated.
