Wet cat food and fruit flies

September 12, 2023 7:29 PM

My cat (tax) will only eat wet food. For logistical reasons I need to use an electronic feeder. However, I seem to have a fruit fly infestation in my apartment and they have discovered the food. Now literally within an hour or two a serving of food will have at least 5-6 flies crawling on it, and obviously neither my cat nor I are happy about it. Below the fold, what I've already tried and does not work.

1. I've tried putting traps near the feeder (currently I have a storebought poison trap and a homemade apple cider vinegar trap right next to the food). This attracts and kills some flies but most of them ignore it.
2. I always flush leftover food down the toilet, not in the trash bin, so there shouldn't be any consistent breeding sites inside the feeder itself (I have tested and none hatch when I wrap the device in a plastic bag). I rinse out cans before recycling them so there shouldn't be consistent breeding there either.
3. I've tried pouring boiling water down the drains in hopes of getting rid of the source of the infestation that way. It has not worked.
4. I've tried locating an onion or potato or any other decaying fruit or vegetable that might be incubating the flies. If it exists, I haven't been able to find anything like it. I live in a large apartment building so it's likely the flies can come in from some other unit, and it's been hot lately so they're likely breeding quickly.
5. I've tried moving the location of the feeder. This works for one day and then the flies return very quickly.
6. I've tried temporarily switching to a non-electronic feeder. Once the flies find it, game over.

I'm at my wits' end here. What can I do? I'm so sick of these things.

posted by derrinyet to Pets & Animals (6 answers total)

Response by poster: Oh, and because I can't be home during the day I can't rely on single serving portions, and the cat will not eat a consistent amount or on a consistent schedule to make this feasible.
posted by derrinyet at 7:31 PM on September 12, 2023

Ideas:

- Work hard to block any gaps/entrances to your apartment. Put fine mesh over the HVAC vents - finer than window screen (look for tulle).

- Put a LOT of traps near where the flies might be coming IN, not near the cat food.

- Install a lovely habitat for a pet praying mantis and/or some carnivorous plants, with mesh that will let fruit flies in but keep the praying mantis in its home.

- Important - capture some of the flies and make sure they are fruit flies - if they are fungus gnats or drain flies, a different kind of trap is needed

- See if a collar-activated feeder access system exists that will block out the flies

- Take yourself and your cat out of the house for a while, with fly strategies deployed, and see if that helps (I'm not optimistic about this)

- I have no idea if ultrasonic insect repelling stuff would work, or work on fruit flies, ,but it's worth Googling

- Talk to your neighbors, see if they have fruit flies also, and do a coordinated attack

- Make sure there is no _moisture_ around for them

- Cover all your drains and dry your sink habitually. Not sure what to do about the toilet
posted by amtho at 8:11 PM on September 12, 2023 [2 favorites]

I've had good luck trapping fruit flies with a homemade paper cone trap like the one on this page. I don't use vinegar, just a bit of fruit. You don't need several big pieces of fruit like what they show in that picture, just a thumbnail-sized piece is fine. And you don't need a big wide-mouthed jar either; a plastic water bottle or similar will work. But use the paper cone, don't just try using a bottle with a narrow top on its own like they suggest.

Does your cat really care if flies land on the food? They probably aren't a health risk at all. Fruit flies are annoying and I understand why you'd ideally like to completely eliminate them, but if your main concern is that they're contaminating the cat food and making it unsafe, I think you can stop worrying about that.
posted by Redstart at 10:19 PM on September 12, 2023

We have always set up a fan that swivels back and forth whenever trying to get rid of fruit flies- I believe it makes it hard for them to land and eat, breed, etc. aim it at their food sources, use traps too. This has always solved things within days.
posted by chr1sb0y at 2:32 AM on September 13, 2023 [4 favorites]

Get covers for your drains.

Apparently fruit flies do not care for vinegar if they are not very hungry, so they probably won't leave the cat food for a vinegar trap. I would try purchased traps that have the full spectrum of fruit fly attractants, or homemade traps baited with fruit. More than two traps would help- put them anywhere flies might be entering, rather than near your cat's food. You don't need more smelly attractants there. Instead I would put a couple non-toxic sticky traps near the food.

You could assemble a large enclosure with a cat flap for your cat to eat inside.

You could try a motion activated feeder that closes as soon as your cat walks away. If the lid seals well enough, when it's closed the flies should instead go to the numerous traps you've set up away from the food.
posted by oneirodynia at 1:56 PM on September 13, 2023

Counterintuitively, don’t put the trap right by the food, it’s attracting them to that area. Are you catching some flies, at least?

You also may need regular applications of boiling water to the drain - if you have adult flies, they may be laying eggs down there, one shot isn’t enough
posted by momus_window at 2:51 PM on September 13, 2023