My basement is crawling with these incredibly useful flies. They lay their eggs in my tanks and the larvae build mucous tubes and proceed to filter feed until they mature. Then they pupate and hatch into the cutest little fairy-winged fly you've ever seen. Anybody know what they are? They definitely make a good fish food. Everything from fry up to large platies devours them as they hatch out. They do best in tanks with fish too big to eat them. I find them very beneficial. I even have a few in a filter tray on my 125g upstairs.
