Lugworms are marine annelids that burrow themselves underground. They inhabit clean sandy beaches as well as muddy brackish estuaries. They grow in size to about nine inches in length and one half inch in diameter. Their bodies are ringed and segmented and they move by a peristaltic contraction of circular and inner muscle layers. In addition muscles are used during digestion to create a peristaltic movement as the lugworm is burrowing into the ground as it eats sand when moving underground into its burrow.