The adder is the only species of venomous snake found in Scotland. Easily identified by its dark zigzag markings it is widespread, although they are generally timid creatures and not frequently seen. Like other reptiles, they grow until they become too big for their skin. They usually shed this a few times a year with each one coming away in one piece and finding these is often a way to tell that adders are in the area.
They live in many different habitats including heathland, moors and embankments. Being cold-blooded, they particularly like basking in sunny south-facing spots to warm themselves up but they will escape quickly into nearby dense cover if they are disturbed.
When the male emerges from hibernation he will try to seek out a female to mate with. The breeding season can throw up one of the most dramatic pieces of adder behaviour called the ‘Dance of the Adders’. Two males vying for the attention of a single female will wrestle by intertwining their bodies until one forces the other to the ground. Although this looks like a dance, it’s an important power struggle between warring males.
Females don’t breed every year in cool climates. However, when they do, the female’s eggs develop inside her body and she gives birth to live young in late summer. Adders usually have around nine youngsters.
Adders have a varied diet and have been known to take smaller rodents, lizards, young birds and occasionally frogs. They do not chew their prey but swallow it whole over what can be a lengthy period.
Adders rarely bite humans. They are shy animals whose first line of defence is to simply get away. However, if they are disturbed suddenly, or trodden on, they can bite. Being Britain’s only native venomous snake arguably earns them a degree of notoriety. Although adder bites can be painful and have unpleasant side effects, they are rarely life-threatening. Nevertheless all snake bites require prompt medical attention.