[paul.fr]

Or is Ireland the only one?

[DoctorBeaver]

There are none in New Zealand, Iceland and Greenland. Oh, and Antarctica.

[TheHerbaholic]

The UK has grass snakes that can bite you with venom, apparently... I've never seen one and if I did I'd probabley try to catch it with sticks like the legendary Steve Irwin RIP!

[Bored chemist]

Are you getting grass snakes
http://en.wikipedia.org/wiki/Grass_snake
 muddled with adders
http://en.wikipedia.org/wiki/Vipera_berus
(which are venomous).
Anyway, while some bits of the UK have adders, Ireland doesn't.
Incidentally, once you had made the poisonous snake angry, what would you then do?
Last time I saw an adder I looked at it and left it alone. It did the same to me.