Being a legless lizard, the slow worm (Anguis fragilis) is often mistaken for a snake. However, there are certain features that separate the slow worm from snakes, including the presence of eyelids and ear openings. This species can be locally abundant and, in Britain for instance, it is likely to be the most commonly seen reptile. Adults have a smooth, shiny appearance, and a grey or bluish belly. The male and female differ in appearance; the female is usually brown, copper-coloured or red on the back, with brown or black sides, often with lighter iridescent flecks. In many individuals there is a dark stripe passing along the middle of the back and stripes running along the sides of the body. The male varies in colour, being greyish, brown, or coppery- or reddish-brown, typically without stripes. The male usually has a broader, longer head than the female. Occasionally, individuals may have blue spots, a feature that is more common among males than females. In juvenile slow worms, the back is iridescent silver, gold, bronze or copper and the sides are brown or black.