Rattlesnakes mainly feed on small mammals and birds. They also eat snakes such as other rattlesnakes and garter snakes, lizards, frogs and large insects such as grasshoppers.
The small mammals rattlesnakes feed on include rabbits, rats, mice, gophers, squirrels and prairie dogs. They prey on birds such as quails, owls, mockingbirds, sparrows and meadowlarks. They hide and wait in ambush for their prey or sometimes pursue it into holes. The pits between their eyes and nose are heat-sensitive and help them locate prey even in the dark. Rattlesnakes incapacitate or kill their prey by injecting it with venom from sharp, hollow fangs in their upper jaws. Fangs normally lie folded against the roof of the mouth and extend when biting. Most rattlesnakes have hemotoxic venom that damages tissue, disrupts blood clotting and causes necrosis. If the prey does not die immediately, a rattlesnake uses scent to track the animal.
After a rattlesnake verifies that its prey is dead, it locates the head by scent and swallows the prey head-first. This enables the arms, legs and wings of the prey to fold in, making ingestion easier. A rattlesnake's strong gastric juices enables it to digest the entire animal, both flesh and bones. If the prey is large, the rattlesnake finds a safe place to curl up and digest the meal.