I saw a post or webpage before I had a fly problem where someone got larvae in the mail. It was a type of bug (maybe another kind of fly?) that lives off the larvae of big black flies and lives in the poop. They said it worked great and they hadn't had a fly problem in years.....I've been trying to find it again since we always seem to have flies but no luck! Anyone ever hear of anything like that? I'm starting to think it was just a fantasy!!!