The species is native to the southwestern United States and adjacent northeastern Mexico.

[citation needed] As the common names imply, H. jani is a primarily nocturnal snake.

[citation needed] The diet of H. jani consists of primarily lizards, but it will also eat smaller snakes and occasionally soft bodied insects.

[citation needed] H. jani is an oviparous species that breeds in the spring rainy season, laying 4–6 eggs that take approximately 8 weeks to incubate before hatching.

[2] Nota bene: A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than Hypsiglena.