Cluster & Swarming Flies
These flies may be found in large numbers in houses, usually lofts,
causing annoyance to the occupants. They enter during the autumn to hibernate
and leave in early spring, sometimes appearing on warm winter days. It
is at these times when they become a nuisance and treatment is necessary.
There are 3 types of cluster
fly: cluster fly, parasitic on earthworms, autumn fly, and green cluster
flies, both breed in cow dung. All 3 species lead solitary lives except
when they gather in the autumn to hibernate. |
Before moving into their
hibernation place they will collect on the outside of buildings, especially
on sunny walls before finding their way inside to form clusters of many
thousands in such sites as roof spaces, under tiles, window frames and
in window sash boxes. They are not a health hazard in the same way that
House Flies are and are only coming into the building to hibernate, not
to breed or feed.
Once a hibernation site has been chosen the flies
descendants will use the site, the memory of the site seems to be passed
on to subsequent generations. It is not understood how this happens. |
