Pinchy Has an Itch

Last week, I told you that small crayfish groom off their branchiobdellids.  Intermediate-sized crayfish try to groom off their branchiobdellids, but the crayfish can’t reach all of the worms.  Specifically, they can’t reach the worms that hang out on that one place on their dorsal carapaces.  Have you ever had an itch on your back that you couldn’t reach?  Yeah, that’s the story of the intermediate-sized crayfish’s life.