In Finland few dairy farms have suffered from a very strange problem. Birds called great tits (latin name Parus major) have gone to cow sheds and have pecked the udders of cows so that some cows must even have been slaughtered after the bird attacks. Nobody knows the reason for this very odd behaviour, but it is supposed that the birds are after milk fat. The winter has been unusually warm in south Finland but unusually cold and snowy in north Finland where the most of the attacks have happened.