Hermit Crabs just love their shells. But they don't get attached, because as they grow, the soft-bellied crabs need to swap out their borrowed homes for new shells, allowing a smaller crab to take the used abode. This real estate bargain takes place in coastal waters worldwide. History: Crabs predate dinosaurs - they've survived several mass extinctions and continue to flourish today. The group to which crabs belong, crustaceans, stretches back to the early Cambrian period, a time when the vast majority of phyla existing today first made their appearance. Scientific Name: Pagurus berhardus. Characteristics: Looking fine in their borrowed shells, these Hermit Crabs are ready to join an ocean-themed party or school unit as giveaways, study tools, or prizes. Size: These mini Hermit Crab figures are about an inch long. Imagine putting some legs on a large blueberry to get a sense of the size. All of our products are Non-toxic and BPA free. 192 Pieces Per Bag.