Reptiles
Florida Worm Lizard
Rhineura floridana · also called Florida worm lizard, thunderworm
The Florida worm lizard looks so much like an oversized earthworm that most people who ever see one assume that is exactly what it is. It is actually a reptile, North America’s only native amphisbaenian, a limbless burrower that spends nearly its entire life underground and can push through soil backward just as easily as forward.
Overview
The Florida worm lizard, Rhineura floridana, is found only in the sandy soils of peninsular Florida and a small part of southern Georgia. It hunts earthworms, termites, and other soil invertebrates entirely underground, rarely surfacing except when flooded out by heavy rain.
Neither snake nor lizard
Belonging to its own distinct reptile lineage, the amphisbaenians, it has a blunt head and tail similar enough to move efficiently in either direction through its burrow. Its folk name, thunderworm, reflects how often surface sightings coincide with thunderstorms flooding its tunnels.
Status
Least Concern — reasonably common across its narrow sandy-soil range, with an underground lifestyle that shields it from most surface threats even as development pressure grows in parts of Florida.
Florida Worm Lizard: common questions
Is the Florida worm lizard a snake, a lizard, or something else entirely?
It is neither, technically. The Florida worm lizard belongs to a distinct reptile group called amphisbaenians, which are more closely related to lizards in a broad evolutionary sense but form their own separate lineage with a body plan and underground lifestyle quite different from both typical snakes and typical lizards, making direct comparison to either group somewhat misleading despite superficial resemblance to a legless snake.
How can a Florida worm lizard move backward as easily as forward?
Its blunt, reinforced head and tail are similar enough in shape and structure that the animal can effectively use either end to push through soil within its burrow system, allowing genuinely efficient movement in both directions without needing to awkwardly turn around within a narrow underground tunnel, an adaptation well suited to a lifestyle spent almost entirely underground.
Why is it sometimes called a thunderworm?
This folk name reflects a traditional belief connecting the animal's occasional appearances on the surface to thunderstorms, since heavy rainfall can flood or saturate underground burrow systems, forcing individuals to the surface to avoid drowning, meaning sightings of the otherwise rarely seen species do genuinely tend to cluster around heavy rain events, lending some real basis to the folk association.
Why is the Florida worm lizard restricted to such a small range?
The species depends specifically on sandy, well-drained soil that is relatively easy to burrow through and that supports a reliable population of underground insect prey, conditions found reliably within peninsular Florida and a small adjoining part of southern Georgia but not more broadly available across the rest of the southeastern United States, which naturally limits the species to this specific, geographically narrow range.