As humans are far too large for a venomous snake to eat, nearly all snake bites occur when somebody provokes a snake into acting in self-defence.
In many cases, provocation occurs by accident, for example, when a person accidentally steps on a snake while out walking. However, sometimes snake bites occur as a result of someone deliberately provoking a snake by:
- kicking it
- striking it
- trying to pick it up
How adder venom works
Adder venom contains two kinds of toxins (poisons) that are designed to kill or immobilise the snake’s prey:
- haemotoxins, which attack the circulatory system (heart and blood)
- cytotoxins, which attack the cells in the tissue around the bite
Haemotoxins
Haemotoxins can cause a fall in blood pressure and prevent blood from clotting, which causes bleeding. This may result in:
- tissue and organ damage
- loss of consciousness
- death
Cytotoxins
Cytotoxins cause blood and plasma (the liquid part of blood that contains antibodies and other proteins) to leak into the tissue in the area of the bite. This can damage and kill tissue cells and result in the affected tissue:
- becoming severely swollen
- bruising
- blistering
- scarring
Where adders live
You can find adders in:
- mainland England
- the Isle of Wight
- Wales
- Scotland
- some of the Inner Hebridean Islands (a group of islands off the west coast of Scotland)
Adders are not found in Ireland or in the:
- Channel Islands
- Scilly Isles
- Isle of Man
- Outer Hebrides
- Orkney Islands
- Shetland Islands
