Sand Crabs are also known as mole crabs or sand fleas. These crustaceans are smaller than a human thumb. The two species predominant on Florida beaches are Emerita talpoida and Emerita benedicti. They are silvery or white in color and seem transparent. The Crabs have antennae, which they use to catch plankton for food. They have no claws and do not bite or sting. The Sand Crabs live between two to three years. The crabs are food for fish, Florida shorebirds, and water birds. They feed on micro-organisms found in the Florida beach sand. That means that they ingest any toxins that might be affecting the shore or the water. Environmental engineers and scientists are able to conclude the health of the ocean based on the condition of sand crabs.