01/28/2026
🦟 The "Sleepy" Winter Guest: 5 Facts About Cluster Flies
Ever notice those large, slow-moving flies buzzing around your windows on a sunny winter day? They aren't your typical houseflies—they’re Cluster Flies!
Here’s why they’ve decided to move into your home this winter:
1. They are "overwintering" experts. Unlike houseflies that breed in trash, Cluster Flies spend the summer outdoors. When the WV temperatures drop, they crawl into the nooks and crannies of your siding and attic to hibernate.
2. They love the sun. On warm winter days, they "wake up" and head toward the light. This is why you usually find them clustered (hence the name!) around windows or lamps.
3. They aren't interested in your food. They don't lay eggs in your kitchen and they don't carry the same diseases as filth flies. Their larvae actually develop inside earthworms outdoors!
4. They follow the leader. These flies release a "clustering pheromone" (a scent) that tells all their friends exactly which crack in your wall is the best place to hide.
5. Squashing isn't the best idea. If you crush them, they can leave a greasy spot and a faint, sickly-sweet odor.
💡 Pro-Tip: The best way to handle them in the winter is a vacuum cleaner with a hose attachment. Just suck them up and empty the canister outside!
Have you seen these "zombie flies" around your house lately? Let us know in the comments! 👇