How do you tell male AND female hermit crab apart?

Male hermit crabs have a larger left claw and a smaller right claw, while female hermit crabs have two claws that are about the same size. This difference in claw size is most noticeable in larger hermit crabs, and can be difficult to see in smaller crabs.

Male hermit crabs also have a pair of pleopods, which are small appendages located on the underside of their abdomen. These pleopods are used for reproduction, and are not present in female hermit crabs.

Additionally, male hermit crabs typically have a longer and narrower abdomen than female hermit crabs, while female hermit crabs have a shorter and wider abdomen.

These differences can sometimes be subtle, and it can be helpful to compare multiple hermit crabs to get a better idea of the differences between males and females.