An adder is a type of snake belonging to the family Viperidae, commonly found in Europe and parts of Asia. It is known for its distinctive zigzag pattern along its back, which helps it blend into its surroundings. Adders are typically small to medium-sized snakes, with adults averaging around 60 to 90 centimeters in length. They are often seen basking in the sun and are most active during the warmer months. Adders are non-aggressive but can bite if threatened. Their venom is relatively mild compared to other snakes, but it can still cause pain and swelling in humans. They primarily feed on small mammals, birds, and amphibians. In some regions, adders are protected by law due to habitat loss and declining populations.