The Adder also known as the Common viper is of a dark brown colour with a distinctive V pattern on the back of the head and a zig-zag dark marking along the back of the body. Colours can vary slightly with a darker almost blue black colour being reported. They normally grow to between 50 and 65 cm although old females have been reported over a meter in length making them much larger than the Slow Worm which is often mistaken for a snake and are generally shorter and fatter than the dark green grass snake. As they are vipers the eggs develop and hatch in the body of the female Adder and a brood is typically 10 young of about 16cm long which are born in mid summer. Adders begin to breed at 5 years old and have an average life span of 15 years
Unlike the Grass snake Adders do not like wet areas although they can like most snakes swim. Preferred habitat is heath land and cliff tops which allow them to bask in the sun easily. During winter they hibernate and frequent the same place to do so year after year, (such places are sometimes called snake pits by local people). They are skilled predators and hunt a wide variety of small creatures, such as voles, small rodents, snails, insects, lizards and small bird eggs. They often hunt at dusk and during the first few hours of darkness as this gives them the best advantage over their preferred prey but as they are cold blooded they need to bask in the day ready to hunt at dusk. They are hunted themselves by foxes, badgers and some species of owl.
If you encounter an Adder then give it some space and it will almost certainly leave, they are impressive and attractive creatures and will not bite unless provoked. Do not attempt to handle.Article courtesy of Tristan Dugdale-Pointon, originally posted at the Storm Crow Survival website