Many other animals "shed" their skin, not only snakes...as in the last post.... Crabs (and other crustaceans) cannot grow in a linear fashion like most animals. Because they have a hard outer shell (the exoskeleton) that does not grow, they must shed their shells, a process called moulting. Just as we outgrow our clothing, crabs outgrow their shells.
Here a Sally lightfoot crab in the Galápagos is bubbling prior to shedding its skin
![](https://static.wixstatic.com/media/618ad6_b36e40ee53074bf784c9fa59052e930f~mv2.jpg/v1/fill/w_147,h_98,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/618ad6_b36e40ee53074bf784c9fa59052e930f~mv2.jpg)
and here is a full moult of a hermit crab in Hong Kong (its body in the shell does not have a hard outter skeleton as its in the shell!)
![](https://static.wixstatic.com/media/618ad6_b71ce242bcb44b2eb8b23bf561dc631a~mv2.jpg/v1/fill/w_147,h_110,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/618ad6_b71ce242bcb44b2eb8b23bf561dc631a~mv2.jpg)