Male pigs are called, boar. They live solitary in the forrests of Europe and are especially active at night.
Young male boars (2 till 3 year) often live in groups and can be agressive. A funny German name for these animals is Hosenflicker, probably because of the agressiveness of the young boar.
A Hosenflicker is also a young boar who thinks that he is already grown up, or at least he behaves like that. But actually he can onyl sniff at a cachers legs. So often he is frustrated, just like a geocacher who cannot find the cache.