Born an overall light brown, within seven to ten sheds they have assumed the light gray to jet black appearance of their parents. It is not known why this ontogenetic color change occurs, but it is believed to be to provide a more cryptic coloration for the young. Even more intriguing is the fact that the adults themselves are capable of changing color, often being light gray with dark blotches at night, and nearly jet black during the daylight hours. It is the only rattlesnake capable of changing colors in this manner, making it unique among crotalids. Being a small snake, they prefer small prey.
Rodents make up the bulk of their diet, along with an occasional ground-nesting bird.
The stomach contents of juveniles have shown that lizards and amphibians are also eaten when available. One adult was observed in the wild swallowing a young desert quail. After nearly an hour, the snake managed to finish its meal, and then slowly crawled toward a small rock crevice to digest it. Despite all the information I have provided here, not enough is known about this spectacular example of North American herpetofauna. Sadly, this snake is often overlooked and rarely given the attention it deserves, even among rattlesnake experts.