Copy of CP 11 21 clusterfly

At Command Pest Control we pride ourselves on being able to send pests packing. In order to do that though, we have to be able to identify which pests have claimed your home as their own. This month, meet one of the least harmful, yet most annoying, pests that might visit you this fall– the cluster fly.


Cluster flies, attic flies, loft flies and even buckwheat flies are all common and descriptive names for the pollenia rudis. With six legs, five eyes and an annoying “buzz,” these wing-clad insects may appear like a house fly from afar. Up close though, you’ll spy black markings and golden hairs that differentiate them. The biggest clue that you’re struggling with cluster flies vs. house flies? At a whopping 8-10 millimeters long, these pests are nearly 8 times the size, and their sluggish nature reflect that.



Similar to autumn’s other frequent visitors, cluster flies don’t enter homes to feast upon them, rather they’re simply seeking warmth in cold months. Eggs are laid in the late summer and early fall, and hatch into adults within a month. Once fully developed, these swarmers seek warm locations, such as the sunny side of your house, to gather together in clusters. When winter weather drops beneath 50°, they sneak into small openings in the walls of your home to hibernate. They often go unnoticed there until sunny winter days when they crawl out of their void in a confused attempt to reach light.



These pests are notorious nuisances, but not at all aggressive in nature. Outside of the occasional dark-colored spots of excrement on windows and walls, cluster flies do next to no damage to your home or its inhabitants. 



Although these insects don’t lay eggs in human food and thus present no health hazard, their diet isn’t any less cringe-worthy. Cluster fly larvae burrow themselves into earthworm cavities to feed upon them. In fact, these larvae are so exclusive with their diet that adult cluster flies lay their eggs underground in earthworm burrows for easier access. As adults though, these pests choose a more sophisticated diet of flower nectar in their spring-home in your garden.


Fun Fact:

Cluster flies are rapid-producing creatures of habit. They can lay upwards of 260 eggs in their lifetime, and if ignored, will return to the same hibernation location, cluster in tow, year after year. In fact, clusters can grow to be as large as several thousand flies under one roof.

Although we mentioned that cluster flies are not harmful, their presence is both annoying and difficult to shake. Protect your home from unwelcome visitors like cluster flies and others by contacting us to send pests packing.


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