The Prairie Rattlesnake (Crotalus viridis) is a species of rattlesnake native to North America, from southwestern Canada to northern Mexico. They can live in a variety of habitats, from prairies and grasslands, to deserts and scrublands. They have one of the largest native ranges of any rattlesnake species, and are found further north than any other rattlesnake. They often are the main predators of prairie dogs. But prairie dogs have shown many times to be aggressive to these snakes, biting, harassing, and even mobbing these snakes. They'll even chase them into a burrow, and bury the snake alive. Prairie rattlesnakes also have to deal with bigger predators like roadrunners, coyotes, bobcats, owls, hawks, eagles, cougars, spotted skunks, badgers and kingsnakes. These snakes are closely related to the eastern and western diamondback rattlesnakes. Their venom consists primarily of cytotoxins, which attack tissues, with a mix of hemotoxins and neurotoxins that attack the blood vessels and nerves, respectively. Like all rattlesnakes, they use this venom primarily to take and digest prey, and secondarily as a last line of defense against attackers. They are pit vipers with the ability to see the heat given off by other animals, allowing them to strike at prey with accuracy even in total darkness.