This class pet is named Shelby, and she is one very lucky hermit crab. Why? Because she’s about change into a brand new shell that fits her growing body. We’re lucky because we get to see her make the move.
More on hermit crabs and their shells from wikipedia:
The tip of the hermit crab’s abdomen is adapted to clasp strongly onto the columella of the snail shell.
As the hermit crab grows in size, it has to find a larger shell and abandon the previous one. This habit of living in a second hand shell gives rise to the popular name “hermit crab”, by analogy to a hermit who lives alone. Several hermit crab species, both terrestrial and marine, use “vacancy chains” to find new shells: when a new, bigger shell becomes available, hermit crabs gather around it and form a kind of queue from largest to smallest. When the largest crab moves into the new shell, the second biggest crab moves into the newly vacated shell, thereby making its previous shell available to the third crab, and so on.
But don’t be fooled by that name! Hermit crabs are actually social animals that prefer groups. From Hermit Crab Patch: “In the wild, hermit crabs live in large colonies and are commonly found piled up on one another when sleeping.”