"K" wrote
Stewart Robert Hinsley writes
Wally writes
I have a plastic compost bin, like an upside down
dustbin, all working very well but just recently when
I remove the lid to add something to the contents, I
am attacked by a million small flies.
Should I do something to get rid of these or are they
doing any good in there ??
If they are working on the compost like the worms do
I can put up with them but if they are doing no good
then they will have to go.

Probably sciarid flies (fungus gnats, fungus midges). They can be a
problem in seed trays, but I don't know of any reason that they would be a
problem in a compost bin.

Or possibly fruit flies?
They'll get bored and go elsewhere when there are no more rotting fruit
smells to attract them.

We get Fruit Flies at all times of the year in our Green Plastic Darlek
where we pour the veg peelings and fruit bits.

--
Regards
Bob Hobden
just W. of London