Shoo fly, don't bother me. I don't need your company.

December 23, 2011 6:33 PM

Can you help me identify these little flies?

I apologise in advance for the poor pictures but they are incredibly difficult to shoot because of their size. The graduations on the ruler in the pictures are millimetres.
They are in one room of the house only, a shower. I have killed at least a dozen a day for the last week. Every single one I that I can find. But sure enough, there are another dozen or so the next day. If I don't kill any they start to approach plague proportions. They spend most of their time on the ceiling and are very easy to kill, it's like they can't see my thumb approaching. Even if I miss them they only flit a few centimetres away. When I squash them they leave a black smear on the ceiling.
I would like to identify them with a view to discovering where the nest/source/breeding area might be. I am in Sydney, Australia.
Fly: 1, 2, and 3.

posted by unliteral to science & nature (11 answers total)

Those are drain flies, I think. They are attracted to moisture and breed like crazy in the drains. In theory you can run hot hot water down the pipes to kill them, but drain cleaner would probably work better.
posted by mittens at 6:47 PM on December 23, 2011

Yeah those are drain flies. Clean the pipes thoroughly to get rid of them.
You can tape up the drains to see which one they're in, there will be some stuck on it.
posted by Threeway Handshake at 6:51 PM on December 23, 2011

Thank you. I'm off to buy a pipe brush and some Drano.
posted by unliteral at 6:56 PM on December 23, 2011

Yeah, we had drain flies last year, and went through two rounds of foaming Drano before they were gone.
posted by lunalaguna at 7:49 PM on December 23, 2011

Too many years in food service I know, but our exterminators told us the only that would kill them is boiling water poured down the drains twice a day for seven days. This interrupts the breeding cycle twice, and eliminates the eggs. It works, and we stopped spending money on chemicals, which were kind of hit or miss.
posted by halfbuckaroo at 6:38 AM on December 24, 2011 [1 favorite]

Okay, the Drano route didn't get rid of them. I'm away for 10 days so I emptied half a can of Mortein into the drain and sealed it up with duct tape and I'll try the boiling water, when I get back.
posted by unliteral at 7:33 PM on December 28, 2011

I been back for a day now and the insecticide and duct tape seems to have finished them off. Fingers crossed.
posted by unliteral at 6:01 PM on January 7, 2012

Aaand… they're back. I'll try the boiling water now.
posted by unliteral at 5:07 PM on January 15, 2012

I've added a diabolical twist. I have a hand-held steamer and I'm going to steam them out of existence. It sure is smelly steam cleaning a drain though. On the plus side, you could eat a meal from my bathroom drain.
posted by unliteral at 4:17 AM on January 17, 2012

The steamer does not seem to kill them all, still have one or two fuckers there each day. Going for the boiling water cure.
posted by unliteral at 5:30 AM on January 26, 2012

Okay, the boiling water didn't work either. I'm going back to my original insecticide and duct tape with extra doses of spray every couple of days. I did this yesterday afternoon and when I had a shower in the evening there were no flies, however… when I had a shower this morning there were dozens of them. I think they have established another colony in the shower outlet drain. Because of the complications of drying that area enough to get duct tape to stick I'm just going for a spray in the morning and at night.
On a related note, now I know about them I see these flies around a lot, particularly in public toilets. The one at Circular Quay railway station is in plague proportions. You have to hand it to a fly that can thrive in the litres of tourist piss that is showered upon them everyday.
posted by unliteral at 2:01 PM on February 5, 2012