Types of burrowing snakes

Phalotris is a genus of small snakes in the family Colubridae, the largest and most diverse snake family on Earth. Colubridae is a broad grouping that holds the majority of the world's snake species, most of which are harmless to people. Within that family, Phalotris belongs to a lineage of New World snakes adapted to a burrowing, secretive life, and the genus currently includes roughly 18 recognized species.

These snakes live in central and southern South America, across countries including Brazil, Paraguay, Argentina, Bolivia, and Uruguay. They are strongly fossorial, meaning they are built for life beneath the surface. They favor sandy or loose soils, grasslands, and open savanna-type habitats where they can move easily through the ground, and they are rarely seen above ground except after heavy rain or when soil is disturbed.

Phalotris snakes are recognized by their small, slender bodies, smooth scales, and a head that is not much wider than the neck, all features typical of a burrowing snake. Many species carry a striking color pattern: a black-and-pale collar or nape band behind the head, often over a reddish or coral-toned body. This bold banding is the easiest field cue, though exact pattern and color vary from species to species and confident identification is best left to a regional expert.

On venom, honesty matters. Phalotris is rear-fanged (opisthoglyphous), carrying enlarged grooved teeth toward the back of the upper jaw rather than front fangs. Most rear-fanged colubrids are of little medical concern to humans, but Phalotris is a documented exception: a serious envenomation from Phalotris has been reported, including significant bleeding effects. For that reason no wild snake of this type should be handled. If a bite occurs, do not attempt first aid procedures or remedies; contact emergency services or, in the US, Poison Control at 1-800-222-1222 right away.

Ecologically, these are quiet, low-profile predators. They forage underground and in leaf litter, preying on small prey such as other snakes, amphibians, and invertebrates, with diet varying by species. Like many colubrids in this group they are egg-laying. Their secretive habits mean much of their behavior is still poorly documented, and several species are known from only a handful of specimens, so much of what is genuinely known comes from broader patterns in burrowing colubrids rather than detailed study of each species.