Does vinegar repel flies?

Vinegar repels some types of flies, while attracting others. Most biting flies, such as deer and horse flies, dislike the scent and taste of vinegar. On the other hand, cider and other fruity vinegars attract fruit flies.

Homemade sprays that contain vinegar are commonly used to repel flies around livestock. A mixture of 2 cups of apple cider vinegar, 1 cup of water, 1 cup of mineral or baby oil, 1 tablespoon of eucalyptus oil and 1 tablespoon of citronella oil repels flies around animals when sprayed on the fur or applied with a cloth.

On the contrary, vinegar makes a great bait for fruit fly traps. A glass filled with vinegar is covered with plastic wrap with a slit in it. The flies go through the slit in search of the vinegar and are unable to escape.