All reptiles are cold-blooded creatures and in winter they hibernate under logs or discarded building material or in burrows in soft earth, where they can keep warm and out of the sight of predators. On cold days, reptiles are very slow moving and make easy meals for foxes, badgers, buzzards and their many other predators. To warm up their bodies in the morning, reptiles bask in the open: they gain their body heat from the sun rather than from the food they eat. On very hot days most reptiles retreat to damp shady places to avoid overheating.
At least once per year, generally in the summer months, reptiles shed their scaly skins, a process known as sloughing (pronounced 'sluffing'); in doing so they are not only able to grow bigger but also to get rid of skin parasites. The skin is not the only part of a reptile that gets renewed regularly: they also grow new teeth continuously.
Several kinds of lizards, including the slow worm, are able to grow replacement tails if their original tail gets broken off, although the replacement tail is not an accurate replica of the original. When cornered by a predator the lizard can even release its own tail, which snaps at a special weak point and continues wriggling in front of the predator, distracting it and allowing the lizard time to scurry off to safety.
Some reptiles lay eggs, while others - in Britain just the adder and the common lizard - are viviparous, which means they give birth to live offspring. The jaws of a snake are surrounded by extremely flexible skin and are uniquely able to separate entirely. By temporarily dislocating its jaw, a snake can swallow its food - small mammals, amphibians or birds' eggs, for example - whole, without chewing it.
Reptiles are protected under the Wildlife and Countryside Act of 1981. It is an offence to intentionally kill, injure, sell or advertise for sale any of Britain's six native species; and, because they are so rare and need extra protection, it is an offence even to possess, handle, capture or disturb smooth snakes and sand lizards. Under certain circumstances a special licence may be granted to allow researchers to study the rarest of British reptiles. On 2nd January 2002, when this page was prepared, the relevant authority for England was English Nature, and for Wales the licensing authority was the Countryside Council for Wales. (Please check via the Department of the Environment, Fisheries and Rural affairs and the National Assembly for Wales for any updates to the licensing arrangements.)
There are also strict laws controlling the import and keeping of exotic reptile species. In particular, anyone who keeps exotic reptiles is prohibited from releasing them into the wild, where they might have a damaging effect on native species. Relevant legislation includes: