One of my crabs is medium sized, and he was way overdue for a molt. He had his "picnic basket" of food and water inside his shell. The bubble looked like it was going to burst. He finally went down, and stayed down for about 4-5 days. I could hear him scratching on the bottom of the tank. Then quiet. Well this morning, lo and behold, the substrate starts moving and up he comes! What the heck? He has already molted once, so he was already hairy. Can a medium sized crab molt in only 4-5 days? Last time he was down for 2-3 months! Any ideas as to why he would change his mind about molting? He was on the end that didn't have the heat lamp. You think maybe it was too cold? I'm so confused! Any input from you experienced crabbers would be greatly appreciated. Thanks.