My little spider that I was trying to get to poop finally went, kinda. He has a lot of wet paper in his tub, but it wasn't color to it, and there were a couple of pebble looking poops, not a true poo. But he has always been that way. But I noticed a big lump close to his vent, it is kinda moveable, and is pretty noticeable. He looks very deflated back there now that he has gone. Does anyone know what this lump is or caused by?