I have the dreaded gnats in my cricket and roach bins, but they aren’t the phorid flies…just soil gnats or fruit flies. To make life easier for my pet sitter when I went away, I set up my crickets bioactively (the roaches were already bioactive). Well, I guess the sitter put out too much food for them and the gnats/flies came. It’s mainly the cricket bin, and I can’t do much about it as it’s now got a bunch of baby crickets hatching in it. Just being careful not to overfeed and letting it all dry out.