Atlantic Mole Crab, Emerita talpoida Atlantic Mole Crabs, also known as sand crabs, live along the swash zone (where waves crash on the beach). They feed on plankton and move up and down the beach as the tides change. If you dig in the sand at the swash zone, you can dig up these small tan crabs. Mole Crabs are harmless, as they lack pinchers and only move in one direction, backwards.  

http://www.loyno.edu/lucec/natural-history-writings/mole-crabs

Thank you,
Susan Brown 

Wonderful!  Thank you, Ms. Brown!