Cluster Flies

Appearance

• Dark grey–olive thorax clothed with crinkled golden–brown hairs.
• 6–10mm in length
• Wings overlap when at rest. Sluggish in flight.

Lifecycle

• Eggs laid in soil.

Habits

• Often found in large numbers in roof voids in Autumn where they hibernate over the winter period.

Cluster flies migrate from the outside conditions into the lofts of house and farm buildings during the winter season. Obvious signs of an infestation include large quantities of lethargic/dead flies around windows. Once in roof spaces the flies will stay in hibernation until spring.