10-20 inches. Pale gray or tan above, with a row of dark blotches or spots down the back and one row on each side; reddish or orange band present down the middle of the back, and wide black band along the side of the head; underside whitish, gray or tan with brown blotches or spots; scales keeled and in 21-23 rows. The rattle is very small in contrast to those of the other rattlesnake species.
Pygmy rattlesnakes occur in wooded areas, but tend to avoid swamps. They favor areas with a grass understory such as pinelands and dry coastlands, but also occur in palmetto flatwoods. They give birth to from 4-14 young.
Upland areas and pine flatwoods in the Florida Parishes and northern and central Louisiana, southwest to Calcasieu Parish. Isolated populations are in the west edge of the Atchafalaya Basin-Vermilion River area, the salt dome islands around Cote Blanch Bay, and liveoak ridges from the New Orleans area southward and eastward.