Went looking for these under the bridge at Beaver Dam Road and 4th Street NE. Found one, but it was tiny, probably 1/3 the size of that first post picture. Didn't have a net, so it's kind of tough when you turn over a rock, everything is murky, and by the time the water clears, anything that was under there has had plenty of time to swim away. Was fun with the children anyway.
So what's the life cycle of these things? They active right up until the water freezes?