Bugs

that shud do the trick...when i had that issue a couple years ago the gnats was comin in an out of the drain holes too at the bottom too..but i was over waterin em and they love moisture...lol...i used spray bottle with the mix an soaked the soil...GL

had them in my kitchen drain last year a friend works in pest control and told me to pour boiling water down the drain twice a day for couple of days because they lay there eggs up underneath and the steam kills the eggs it worked for me there life cycle is only like 2-3 days but they can multiply quick.