Do you mean "They are easy to tell if you have them, because they come to the top soil when your plant is being watered, if you find you do have them, use Fungus Gnat Killer (“B.T." a non chemical,biological control) in the powdered form. One application should kill it, just to be safe repeat every 7 days to kill off the larvae. Tobacco juice kills them as well! And nematodes." ?
I went to home depot to look for any Fungus Gnat Killer, or any product that listed that it killed "fungus gnats" but found nothing. All I found was the spray that I used. I think it worked/is working