Adult adder (Vipera berus) on a woodland floor. The adder can be found throughout most of Europe and as far as East Asia. They are particularly common in woodland and heathland, where they like to sun themselves in the open areas. Adders naturally retreat from humans and usually bite only when really provoked. Their bites are rarely fatal but can be very painful. Adders feed primarily on small mammals, such as voles and mice, but also small birds and lizards. They can live for 10-15 years in the wild, though they sometimes fall victim to other predators, such as birds of prey, crows and foxes. Photographed in April, in Dorset, UK.