Although they are lizards, slow worms have lost their limbs completely and are often mistaken for snakes. Slow worms typically grow to between 40 and 50 cm (16 and 20 in), with the females slightly larger than the males. The tail makes up around half of its length, but is indistinguishable from the body.
As their name indicates, slow worms are slow moving and can be easily caught. Like many lizards, slow worms can shed their tails to distract predators. The tail regrows, but rarely to the length of the original.
Slow worms can be distinguished from snakes by several features: their eyelids, which snakes lack entirely; their small ear openings which again snakes lack; and their tongues, which are notched in the centre rather than completely forked like a snake's.
Slow worms are typically grey-brown, with the females having a coppery sheen and two lateral black stripes, and the males displaying electric blue spots, particularly in the breeding season. They give birth to live young; the young are about 4 cm (1.6 in) long at birth and generally have golden stripes.
Slow worms have grooved teeth which allow them to grab and swallow whole their soft invertebrate prey, such as slugs, hairless caterpillars, and earthworms. Snails are usually avoided, except when they are still very young and the shell can be broken easily.
Slow worms are frequently found in garden compost heaps, or any place both warm and protected. A slow worm can live in the garden. They range across most of Europe, and into parts of Asia, although they are restricted to temperate and humid habitats. They hibernate from October to February/March, both communally and solitarily, and sometimes share hibernating sites with other reptiles.
- Genus Anguis