Oh, yes, I've seen them move backwards. My cousin used to catch them in the creek in Tennessee. This reminds me of what Anu said when his W.A.D. was crabwise: If we were to look up the term `humanwise' in a crab's
dictionary, chances are it would mean `sideways'.
That line just set me off into envisioning a whole underwater scenario, with crabs using their library, etc.!
My husband and son have eaten crawdads (another term for them), but I won't touch one. I really prefer food that doesn't look back at me.