I thought I had fruit flies.
But there’s no fruit outside of a can. No produce on the counters or in the trash. So where are these little black fruit fly things coming from?
The kitchen sink drain is where. Tiny bits of vegetation languishing in the trap. Don’t ask me why the flies don’t drown, but they don’t.
To get rid of them, the drain must be completely cleared. An inexpensive way to do this is with baking soda and vinegar.
Put 3/4 cup baking soda down the drain (both drains if it’s a double sink), encouraging it to fall in by stirring it with a fork or spoon. Then pour on half a cup of vinegar. It will boil and spit, so move your face away. When it settles down, pour more vinegar. Keep doing that until all the boiling noise is from down inside the pipes, not up in the visible drain area. Leave it alone for an hour or so and then flush with plenty of hot water.
This also works well for clearing a partially blocked drain.