This video from South Yorkshire in England is called Adders mating (Vipera berus).
2015 is not just the Year of Vincent van Gogh. And the Year of the Penny Bun for mycologists. And the Year of the Goat in the Chinese calendar (starting on 19 February). And the Year of the Badger.
The Dutch RAVON herpetologists have decided that 2015 is the year of the only venomous snake in the Netherlands: the adder. They hope that this year there will be more measures for a better environment for adders, like tunnels enabling them to cross roads.
See also here.