They look much bigger because they have very long legs. Fiddler crabs are abundant in the mud flats at low tide, They are smaller than a dime and live in holes they dig in the mud. The males have a single pincer claw, which they wave constantly to attract females. When the tide comes in, Fiddler crabs go into their holes and plug the openings with a mud plug, thus staying relatively dry. These crabs are also spooky - to see them you must be still, or they will vanish into their holes.
Hermit crabs live in discarded shells .
As they grow, they outgrow the current shell and move to a larger one. Hermit crabs are common on the beach. Look in the opening and you will barely see its hard legs covering the opening and providing protection. Stone crabs are less common. They can grow up to five inches in width, and are reddish brown in color.