Head. Venomous snakes have distinct heads. While non-venomous snakes have a rounded head, venomous snakes have a more triangular-shaped head. The shape of a venomous snake's head may deter predators.

What kind of snake has a triangular head?

The shape of the head provides a clue. All of the dangerously venomous snakes in Europe are vipers, like the adder or the horned viper. And all of them have a triangular head. The shape is so distinctive that you can easily recognise these snakes from a distance.

What shape head Do poisonous snakes have?

Venomous snakes typically have broad, triangular heads. This may sound odd because most snake heads look similar, but the difference in shape is seen near the snake's jaw. A venomous snake will have a bulbous head with a skinny neck because of the position of the snake's venom sacks underneath its jaw.