It shows two male adders, in a dance during the mating season of this species. The best dancer will be able to mate with a female.
Bargerveen reptiles: here.
May 2011: The family of a nine-year-old girl who made the headlines recently after being bitten by an adder in Hampshire has spoken up in support of snakes. Tylar Butcher, who was holidaying in the New Forest, was rushed to hospital after being bitten while walking with her family: here.