Pseudoleptodeira

Pseudoleptodeira is a small genus in the family Colubridae, the largest snake family and a catch-all of mostly slender, agile, egg-laying species. The genus name means false Leptodeira, a nod to the true cat-eyed snakes (Leptodeira) that it closely resembles. The best known member is the False Cat-eyed Snake (Pseudoleptodeira latifasciata), a slim nocturnal snake of western Mexico. These snakes carry the classic cat-eyed look: a relatively broad head set off from a narrow neck, large eyes with vertical, slit-like pupils, and a banded or blotched pattern over a pale ground color. The vertical pupil is a common adaptation in night-active snakes and helps separate this group from round-pupiled day hunters.

Members live in the dry forests, scrub, and rocky hillsides of Pacific-slope Mexico, where they are active at night and shelter by day under rocks, logs, or leaf litter. Like many small colubrids in this part of the world, they feed largely on small vertebrates such as lizards and frogs and are believed to lay eggs rather than bear live young, which is the typical colubrid pattern. They are secretive and rarely encountered, so detailed natural-history records are limited; much of what is understood comes from general patterns across similar Middle American colubrids rather than from extensive study of this genus itself.

These are rear-fanged snakes, meaning they have enlarged grooved teeth toward the back of the upper jaw and a mild saliva used to subdue small prey. They are not considered dangerous to people, and there are no records of serious harm to humans from this group. Even so, no wild snake should be handled. A rear-fanged bite can cause local swelling or irritation in some people, and field identification of small banded snakes is easy to get wrong, so it is safest to leave any unknown snake alone. If a bite occurs or you are unsure what bit you, contact emergency services or US Poison Control at 1-800-222-1222 rather than attempting first aid yourself.