"Mentalguy2k8" wrote in message
news:5K_Wn.94783$w51.88115@hurricane...
They're black and smaller than house flies. We're getting a lot in the
garden, they seem to fly/hover aimlessly underneath the washing on the
line (like gnats), but never seem to land on anything.

Same indoors, they congregate in the middle of the room, sometimes a dozen
or two, just moving around underneath the ceiling fan, never seeming to
land on anything. They're coming in through an open door (although an
almost full-lenght curtain is across it, the breeze lifts it at times and
we seriously need the fresh air)


IIRC they are in a mating display - males compete for the females by some
kind of flying antics and so any suitable space for nooky is poulated by the
flies.

If a good place for nooky comes free (e.g. through the previous occupants
being zapped) then more males move in until they have occupied the space
again and are keeping the other males out.

There is a natural maximum density for males and females when this is taking
place.

So either resort to mass chemical assault until there are no more flies in
your neighbourhood, or try and work out what is attracting them.

Indoors, it might be the draught from the ceiling fan.

Outdoors it might be the increased humidity (assuming you have washing on
the line).

Cheers

Dave R
--
No plan survives contact with the enemy.

Helmuth von Moltke the Elder