Question

A familiar tradition in norway involves putting a bowl of rice pudding out for the barn elf. why is this done

Answer 1

This is a cultural tradition that has its roots if folklore of many Scandinavian countries, but it is also found in Norway. In Norway, the bowl of rice pudding is left for the barn elf so he would not turn mischievous and that he will continue to take care of the household's animals. 

Answer 2

Barn Elf is often called as a short man who is placed outside of the house in the fields or between the animals, to take care of them from other animals or birds.

In Norway, A bowl of rice pudding is placed outside for the Short Man, so that he would not turn roguish and would take care of the fields and the animals. Because other animals or birds can come and destroy the fields of can harm the animals. So when this short man is placed, the animals and birds think him to be the real man and don't come near the fields and animals by getting frightened by him.