Is Vinegar Effective Against Gnats? Pest Pros Say It Does More Harm Than Good

If you didn’t know that vinegar is the Swiss army knife of household cleaning and gardening hacks—now you do. Whether it’s replacing cleaning supplies or as an effective weed killer, it seems like vinegar can do it all. You may have heard that you can even use vinegar to kill bugs, but does that work for all of them?

Gnats are often one of the biggest headaches of the summer, so we’ve asked pest pros if vinegar could help save the day.

Does Vinegar Kill Gnats?

Unfortunately, vinegar alone is not enough to solve your gnat infestation problem.

“I have personally used a couple of vinegar mixes, and I haven’t found anything that worked really well,” said Matt Smith, owner of Green Pest Management and a licensed pest control technician. “Yes, it did kill some, but only a fraction of what was there.”

Experts like Dr. Hamilton Allen, a board-certified entomologist and the vice president of technical and safety at Fox Pest Control, actually say that using vinegar against gnats could actually make your infestation worse.

“Contrary to popular belief, vinegar attracts gnats and fruit flies instead of repelling them,” Allen says, “The sour smell associated with vinegar is acetic acid, the same substance found in fermenting fruit, which attracts the flies.”

If you do plan on using vinegar to kill gnats, Allen recommends pouring a few ounces of vinegar in a container and adding a little dish soap. You can hope that the gnats will be attracted to the vinegar and drown, but, as Smith also said, this might not kill enough flies to actually fix your problem.

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Two Things You Can Do Instead to Get Rid of Gnats

Since Smith says DIY vinegar methods haven’t been the most effective in his opinion, he shared with us the two methods that actually solved his gnat problems.

“First, we put sticky traps down in those same areas with a little piece of food on them,” he shared. “Second, we found the source and threw it out. Gnats are a source problem; take care of that source, and the problem goes away fairly quickly.”

For example, if you have indoor plants and are noticing gnats around them the most, take the plants outside to let their soil dry out. This should cut down your gnat infestation considerably.

Allen also recommends finding the source of the infestation as the most effective method for ridding yourself of these pesky buggers.

“A small piece of decaying fruit hidden beneath your fridge is enough food for a female fruit fly to start a family,” he said. “You can also pour bacterial digesters in the drain to decrease the amount of buildup in your sinks. Boiling water doesn’t do enough to remove the flies’ feeding or breeding material in there.”