Hermit Crab - Hermit crabs are decapod crustaceans of the superfamily Paguroidea. Most of the 1100 species possess an asymmetrical abdomen which is concealed in an empty gastropod shell carried around by the hermit crab.
Salt AND fresh water is required! The hermit crab will make up his own mixture of water that he keeps in his shell. Great example of proper hermit crab pools! :) Crabitat Pools by ~GodzillaHermitCrab on deviantART
How to Care for Hermit Crabs. Hermit crabs (affectionately called hermies) are great pets to have. They may not be as cute or cuddly as a puppy, but they are fun to play with and will teach kids the meaning of caring for another living.
SCIENCE FOR CHILDREN-Having already done this, it was a great addition for sand and sensory for even toddlers. Developmentally appropriate for children of all ages depending on what is added. Will abs (How To Make Slime With Flour)