The Western Diamondback Rattlesnake is Crotalus atrox, a widespread, highly poisonous American pit viper with a tail that rattles as a threat or warning. Rattles are made up of small sections of keratin, similar to your fingernails. Rattles are remains of periodic skin sheddings. The older the snake, the more segments to the rattle. Some scientists also believe that younger, smaller species of rattlers may rattle to lure birds and other prey animals. The sounds made are a lot like insects to birds, who'll fly over in hopes of finding a snack. Instead they find a hungry snake. Size:1 1/2" - 2" Long This item has been legally obtained and can be legally sold according to the New York State Department of Environmental Conservation and U.S. Fish & Wildlife Service.