The National Lobster Hatchery uploaded this incredible sped up footage of a molting cobalt blue crayfish (Procambarus alleni). Watch as it wriggles to free itself of its outer layer. From Reference.com:
Next: Molting Japanese spider crab time lapse and Pagurus Bernhardus hermit crabs change their shells.
Crayfish molt because they must shed their hard exoskeletons and grow new, larger ones as their size increases. During the first year of life, a crayfish molts six to 10 times. This number decreases to three to five times during its second year.