I've noticed that animals spawn in groups. If there is some way that they can stay in that group and move together that would be perfect. And a bonus if they can merge with other groups. This is mainly to have a pack of wolves. But you could have a brood of hens, a herd of horse or deer, a sounder of swine(I looked that one up online:)), or a sloth of bears(that one too).

 

There would need to be a limit on how many can be in a group if they can merge. A radius set to determine how far they can wander in the group before coming back. And possibly some sort of logic to set the alpha of the group to set the path the group will follow.