As the hermit crab world turns

Perhaps you know that Tim has three hermit crabs. The first was Sandy Claws, who was given to him as a Christmas present by our neighbors Dean and Stacia. The second one, Hermie Claws, he bought for himself. The third, Dean and Stacia gave to him after they got sick of his hermit crab ways--he was Crabby Cakes, but after being adopted became Crabby Claws. Appropriately so, I might add.
They've added some adventure to our at-home lives. Crabby tends to break out of their bin where we put them for an opportunity for exercise. It's big but the walls are barely too short to stay assured of their incarceration. Any of them who break loose tend to go while under observation straight to Tim's shoes, among all the family shoes that are lined up on the stairs. Crabby has escaped without our immediate notice three times. Twice, he reappeared in the dirty clothes of the laundry room after two weeks of being AWOL. I'd vacuumed in there a few days ago, and yesterday he showed up, walking along minding his own business. I picked him up and he immediately pinched me hard--and when I'd try pulling him away, he pinched harder. I was wrestling to get him off in my pain, and he wasn't letting go. About 3 minutes later he finally released me when I lightly whacked his shell. I gave him to Tim, who wisely held him by the shell and not under the claws.
Today, I looked in their cage and there was Sandy, out of his snail shell, looking a little embarrassed at being found naked. (Whenever they've changed shells before, they modestly waited until no human was watching.) I called to Tim so he could take a look. (It's only a hermit crab, after all! Ha!) We picked up one of the two little huts in the cage, and found what appeared to be the remains of a crab. We were alarmed, thinking that Sandy had eaten one of the other crabs. But when we looked in their shells, they were occupied. I suddenly realized that Sandy had molted and was waiting for his new shell to dry before taking on a snail shell again. The empty hull was not a dead crab but an empty shell. Tim had run into the bathroom in his horror, but now came out to investigate the new thought and to play with the macabre-looking parts; within a few minutes, Sandy found another, larger snail shell and took up residence. It was an interesting lesson in marine biology and a greater understanding of the life processes of his pets. Also a relief; funny how you can come to value the lives of some silly little crustaceans. I suppose if they weren't so cute I wouldn't have even been interested to look in on them.