Don’t be Crabby - Smiling Crab Charm Necklace . A drawing by my 16 year old son of this cute crab was the inspiration of creating this adorable smiling crab charm necklace, whose always happy at the beach. Lexi’s exclusive design, the gold plated crabby is approx. 1” wide. 16” Gold filled chain. It is said that The majority of crabs are nocturnal, and therefore sleep during the day. In general, land crabs sleep on land and marine crabs will sleep underwater. They sleep for the same reason as you and I do – to save energy and to regenerate!