Help me help my tenant with a fruit/drain fly issue

[curves2000]

Hi all,

So I have a puzzling situation where a tenant of mine in an apartment building has an ongoing fly problem. She is adamant that they are coming from the drains in the bathroom and kitchen but when I did a little research, these appear to be super small fruit flies as opposed to drain flies.

She keeps the place spotless so it isn't a matter of "cleaning up" I have tried cleaning the drains with a variety of methods (scrub, baking soda/vinegar) and I also tried a special cleaning solution that's meant for things guck, fats and other debris that flies may survive off of.

Anybody have any additional tips?

Thanks!

[Nufy]

Have you tried a snake to "scrape" the walls of the pipe...

It could be stubborn crap that chemicals wont budge.

[bc-chris]

what about boiling a couple of huge pots of water and then dumping them down each drain??

i know i was told by someone that fruit flies like to lay eggs in drains and the scalding hot water will kill the eggs (that could just be an old wives tail, but it might be worth a shot)

[Cali Panthers Fan]

This is a really common problem here in South Florida. Our exterminator told us to pour 1 cup of bleach down the drain once a day. That will kill any eggs that get laid in a 24 hour period and the breeding cycles will eventually stop. Use fly strips for any stragglers that are flying around after that. You'll be fly-free within a week.

[Boblobla]

Cider vinegar is very good at catching fruit flys for the ones that are currently alive. Put an almost empty container out on the counter with some saran wrap on the top with a tiny hole poked in it. We had issues earlier this year because of a banana left in on of our kids lunch bags and it took care of the problem.

[GGG]

A cup of apple cider vintages and dish soap left out works to. Took about a week to get GE last of the straglers.

[Northendzone]

all of the above plus some fire is the clear answer

[topfiverecords]

If you're unsure they're coming from the drain, an idea I've seen recommended is to put clear packing tape over the drain. Then poke a few holes and any flies trying to escape the drain will get stuck to the tape.

Don't do it after running hot water as it will steam up and reduce the stickyness.