Insect and Spider Identification: Unidentified orange/white caterpillar (Langesund, Norway), 1 by Derpy

Derpy wrote:
My boyfriend found a caterpillar on a cliff, in a forest in Langesund (a lake town). We want to keep it, but although we have provided a correct environment and a variety of leaves from different trees, the caterpillar appears not to have eaten since about 24 hours ago when we caught it (although there are droppings present, so maybe it secretly ate overnight). When found, it was sitting on the ground and not in a tree, so we don't have the information that concerns its feeding habitat. I was hoping someone out there could identify the species of the caterpillar, so we could do a search about what leaves it prefers to eat. Thank you very much in advance, and please view its picture below. :)