not an adder
Brown and olive green? sounds like a grass snake to me, oh and grass snakes do have teeth as I can testify having been bitten by them on more than one occasion.
Also worth pointing out that these are both protected species and you cannot remove them without authority.
Also the chances of being bitten even if it is an adder are very small and most adder bites do not result in more than a little nausea and temporary swelling.
They are not designed to kill creatures of human size and the few deaths in the last fifty years have been on infants or people with prevailing medical conditions.
This is a non story apart from the human idiocy angle.
Biting the hand that feeds IT
