My worm bin is breeding a black colored fly a little bigger than a fruit fly and with heart-shaped black wings. (I think it was introduced through some soil from forcing bulbs mailed to me. I haven't been able to identify the fly, but its rounded wings are very distinctive.) I found lots of skinny yellow thread-like larvae in great masses in my worm bin, and I'm trying to determine if these are red wiggler larvae or maggots from the flies, or some other unwanted creature. These little larvae are about 3/8 inch long, very wiggly, and in clumps they look a lot like a tangle of yellowish rootlets not much thicker than hair. Can anyone verify they are a new crop of wigglers, or something I don't want?

Here is a link that might be useful: vermicomposting forum