Cluster flies are a common household pest in Wisconsin. These flies tend to come indoors as the weather gets colder. They survive the winter by hibernating together in clusters inside wall voids and attic spaces. Cluster flies are black with yellow hairs on their thorax and measure ⅜ to ½ of an inch in length. They are primarily dormant over the winter, but some flies may emerge on warm, sunny winter days.
Why Do I Have Them?
Cluster flies prefer warm environments and normally live outdoors. As the temperature gets cooler, large groups of cluster flies enter houses to overwinter. They invade homes through tiny openings in walls, doors, windows, and vents. Once indoors, these flies will hibernate in attics and walls. On sunny winter days, cluster flies are often seen around windows.
Why Should I Be Concerned?
Cluster flies do not carry diseases or breed indoors. However, their presence can be annoying, as they tend to travel in large swarms. Large numbers of cluster flies will often congregate on windows during sunny winter days, making them a nuisance for most homeowners. These flies will leave a stain when squished. Their droppings also give off a noticeable odor and may stain fabrics and walls.
Treatment & Control
How Do I Get Rid of Cluster Flies?
Getting rid of cluster flies can be a difficult task due to their nesting habits. Sealing cracks around doors, windows, and vents will help prevent fly infestations. If flies have already invaded your home, the most effective way to get rid of an infestation is to contact a pest control professional. At Advanced Wildlife and Pest Control, we offer effective pest services to eliminate your fly problem.