Okay, I know crabs don't "hibernate" per se, but would a crab bury itself because Fall is approaching? My medium-sized crab, Shorty, is usually fairly active. In mid-Sept in Maryland, it's still warm outside, but Shorty disappeared under the substrate and hasn't come up since. He just finished his molt 2-1/2 months ago, so it's not that. I set up a new tank a few days ago and had to disturb him.....he explored his new surroundings a little, then buried himself again. I'm a night owl, and I haven't even seen him coming up to eat or drink! My other two crabs are active and seem quite content. I've had Shorty for several years and he's always been active. Most winters ALL my crabs are less active, but I read that this is normal. Any ideas as to what is up with him? I'm worried! Thanks.