Rattlesnakes eat small mammals, reptiles and insects. A rattlesnake's diet consists primarily of rodents, such as mice, rats and rabbits, as long as those animals are available.
The rattlesnake possesses pit sensors, which are organs that sense the temperature of their surroundings. They identify potential prey by detecting animals and insects that are warmer than the surrounding terrain.
Since rattlesnakes are hunters, they base their diet on availability as well as their size. Larger snakes, such as the Western diamondback rattlesnake, might target birds and gophers for a meal.
Rattlesnakes do not have to eat every day. Many adults eat only every 2 weeks or so to maintain their metabolism, reports the National Wildlife Federation.