Meadowlark,
Thanks for the reply. I catch them with a fairly fine dip net. Usually, about 1/4 of them in a catch are big enough for bait, and the fish really hit them hard when fished around the weeds where they are netted.
I think they eat mostly vegitable matter, mostly algae and decaying plants and occasionally small critters. I have never seen them in murky or stagnant conditions, so I associate them with healthy water. Perhaps they are even partly responsible for the healthy water.