I have these nets in my house and I heard they were called drain bugs. If true how do you get rid of them?

Question

I do not have real house plants or any other plants. I have had some water leakage in my attic

Answer 1

Not sure if this is what you mean, but here goes. From Lincoln-Lancaster County Health Department:

"There are a couple types of small flies that emerge from drains of sinks and seem to hover over the sink area. One type looks like a very tiny moth; the other is a tiny dark-colored fly. Phorid flies may also breed in drains. Most of the time, the infestation is in the gelatinous gunk that lines the drain or from a garbage disposal, but flies can also be produced where there is a problem with broken or leaking pipes.
Control: The fastest way to solve this problem is by cleaning
the drain pipes. Unfortunately, some household products are meant to dissolve clogs — not clean pipes. Bleach and hot
water will not kill fly larvae breeding in the pipes. A “snake” or a stiff brush along with industrial strength drain cleaner will be most useful. Never pour insecticides down the drain."

Answer 2

I think you are referring to gnats. They can appear in houses that have fruit, plants or garbage. You can spray for them.