Snakes in Denmark

Once there were four species of snakes in Denmark. The Aesculapian snake and the Smooth snake are today considered extinct. That leaves the two remaining species: European Adder (Vipera berus) and the Grass snake (Natrix natrix).
The European Adder.
Adders are the only venomous snakes found in Denmark. They use their venom to immobilise prey such as lizards, amphibians, nestlings and small mammals. Adder’s are notoriously shy and will avoid human contact whenever possible. You must be very close to the snake to be bitten. Normally within 25 cm.
Although an adder’s venom poses little danger to a healthy adult human, the bite can be very painful. Adder bites are normally not serious but can be in some cases (eg. for small children)! It is advisable to remain calm and not to panic. The venom is released through the bloodstream and movement such as panicking could increase is spread throughout the body. Medical attention is recommended.
First aid.
Consider the following when bitten or helping someone else:
1) Check that breathing is normal and not restricted
2) Loosen tight clothing around the bite area
3) Remove jewellery and watches if swelling becomes a problem.
4) Seek medical attention.
Most cases can be seen to locally by a medical professional if the casualty is breathing fine with only minor symptoms present.
Call 112 if the casualty’s breathing is inhibited.

Description.
The colour pattern of the adder varies, ranging from very light-coloured specimens with small, incomplete, dark dorsal crossbars to entirely brown ones with faint or clear, darker brown markings, and on to melanistic individuals that are entirely black and lack any apparent dorsal pattern. However, most have some kind of zigzag dorsal pattern down the entire length of their bodies and tails. The lenght of the snake is only about 60 to 90 cm (24 to 35 in).

The Grass Snake
The grass snake is the largest snake in Denmark. It can grow up to 140 cm long. The snake is harmless and not venomous.
Description.
The Danish grass snakes are typically dark (black) in colour with a characteristic yellow collar behind the head. However, the colour may range from grey to black. Grass snakes are good swimmers and are frequently found close to fresh water. Grass snakes prey mainly on amphibians.
Very rarely bite in defence.
Not being venomous, the snake’s only defence is to produce a bad smelling fluid from the anal glands, or sometimes to feign death by becoming completely limp. The snake may also in some cases perform an aggressive display in defence, hissing and striking without opening the mouth. They very rarely bite in defence.
Sources: train-aid.co.uk, NaturGuide.dk, wikipedia.