In spring '05, I put about 10,000 crawdads into my 6-7 acre pond. There is a lot of habitat for them in my pond. You can flip any rock and find some.
I would say that maybe every 50th fish caught will have two pinchers and some antennae sticking out of his gullet. What does this observation mean? Beats me, but I thought I would mention it. I'm not saying that a lot of fish are not eating crawdads in my pond, just that you don't always see evidence of it.