Do not use bleach. Since bleach does not coat the pipes, it will not kill the flies. ... It's the bio-buildup that attracts fruit flies to your drains. It also gives them another place to lay their 500 plus eggs, other than on your fruit and in your plants.

What kills fruit flies instantly?

Pour boiling white vinegar or boiling water into drains. This is a simple way to get rid of fruit flies immediately. Many fruit flies make themselves at home in moist and hidden areas, such as shower drains, sink drains, garbage disposals, toilets, and more.

How much bleach do I put in a fruit fly drain?

Pour a half gallon of water and 1 cup of vinegar or bleach down the drain to sanitize. Pour boiling water down the drain to loosen rotting matter.