Adders should start emerging from hibernation over the next few weeks. Here are five facts about these snakes brought to you by RSPB Scotland’s Jess Barrett.

Five facts you need to know about adders

1. Adders are the only venomous snake in Britain

Of the three species of snake found in Britain adders are the only venomous ones. They use their venom to immobilise their prey, usually small rodents such as voles. Adders aren’t aggressive and prefer to avoid confrontation with humans and domestic animals such as pets. They’ll only use their venom as a last resort, usually if they have been trodden on or picked up so if you see one it’s best to leave it alone. Though their venom is generally of little danger to humans it does have the potential to be serious so if you are bitten by an adder seek medical help as soon as possible.

2. Each adder has a unique head marker

Adders have a dark zig zag pattern down their back and a row of diamonds along their side which you usually can’t see as they slither along. Each snake has a unique pattern on the back of its head, usually in the shape of a “V” or an “X” which means individuals can be told apart. Even if the pattern shape is similar the way their scales are arranged will differ on each snake. Males will grow up to 60cm long while females can grow as long as 75cm.

3. They hibernate over winter

Adders in Scotland hibernate in Scotland between October and March. They start waking up from their cold weather slumber in the first warms days of March, so (weather permitting of course!) they should start emerging over the next few weeks. Adders tend to very secretive; as they come out of hibernation is the time of year you’re most likely to see one as it basks in the sunshine. They tend to be found in heathland, moorland and woodland areas.

4. Females give birth to live young

Unlike most snakes adders don’t lay eggs. Instead the females give birth to live young, the number of which can vary between six and 20, in late August and early September. The baby snakes are exact replicas of the adults only they are around the size of an earth worm. The breeding period for adders is in April and May. It includes the incredible spectacle of the dance of the adders where males spar for the females by rearing up against each other and rolling around on the ground. Such displays can go on for as long as half an hour.

5. Adders appear to have an unblinking stare

In the past people thought the unblinking stare of an adder was an attempt to hypnotise them. In actual fact adders do have eyelids, only they are transparent and fused shut which explains why they don’t appear to blink.