There's a type of fly which hatches out in the walls of old houses. We call them cluster flies. They breed outside, then come into the walls of old houses to rest and change there from larva to fly.Then they appear in large numbers in the house, very dopey, cause mayhem then disappear.
Could be those, MoBrown.
If so there's not much you can do about them. We've had them a few times.
Grandson of New Limerick (Son of New Limerick contd.)

?
