According to Wits University professor Graham Alexander quoted in the Cape Times newspaper, the reptiles have got a bad rap in Africa for biting anything that steps on it.

But he believes many people have trodden on a Puff Adder while walking in the bush and never even noticed, because they were not bitten.

He put this theory to the test in a game reserve just north of Pretoria and fitted a radio transmitter to a snake before letting it loose in the bush. He attached a gumboot to the end of a broomstick, and went looking for the snake to test its patience.

"I first placed the boot five centimetres from its nose and recorded what the snake did. I then dumped the boot on its back," he told the newspaper.

He waited five seconds for a response and the snake "usually" just lay in the same spot. Alexander said after numerous attempts he got one snake to strike. However, this one was moving when provoked and the scientist believed it was a mock strike.

He said snakes bit as a last resort.

The Puff Adder is responsible for many bites in South Africa, releasing cytotoxic venom that destroys muscle tissue.