For the past couple of months I have had a swarm of about 100 very small
flies at the corner of my garage. The swarm seems to stay in one position.
About 4 to 5 feet from the ground and about 1 foot from the wall. The corner
faces north and east. I have repeatedly sprayed them with a fly killer but
as soon as the spray disperses they are back again.

The only thing growing in the vicinity of the swarm is an Ivy. This is about
3 feet away but the flies do not seem to go near to it.

Can someone please advise me what would cause this and how can I get rid of
them.

Many thanks

Les