All rattlesnakes are carnivorous, their primary food sources being rodents, other small mammals, birds, and small reptiles. The behavior of the Black Tailed Rattlesnakes varies over the course of a year. In the spring and fall, they are primarily diurnal. In the summer, they shift to a nocturnal behavior, to avoid the heat of summer. In the winter, they hibernate in dens created and abandoned by other animals, often with other species of snakes. They are variable in their form of locomotion depending on what substrate they need to traverse and will actively change between sidewinding or rectilinear movement. Although it is an able climber and expert swimmer, the Black Tailed Rattlesnake is primarily a terrestrial species and inhabits grasslands, desert areas, and rocky and mountainous areas, as well as high-altitude forested habitats.