Identifying Flying Black Insects?

I've had loads of these little black fly things. I've had people say they are Ensign wasps, Phorid flies, or fungus gnats.

They fly at me sometimes, are found in all rooms either in the window sills or in glue traps by skirting boards.

I live in a first floor flat with no garden, no indoor plants or pets.

Any ideas other than the ones already offered?

Thanks.