I recently bought an arrow crab thinking it would eat bristle worms because I have a serous infestation, I understand everyone thinks there good which I'm not saying there not, I just don't like them, partly because I have hundreds, but I got my crab 2 days ago, and he still hasn't touched a bristle worm,I literally watched some walk on his legs and he didn't do anything, is this normal for them to take there time, or did I just get a bad crab? Any advice??