It's been my experience up until now that horses, even if unfenced, stick close to home. The sim whose horses are currently wandering a little further afield has no close neighbors. If he did, you could say the horses, a mare and her older foal, have never gone much further than the "neighbors' yard," the area immediately surrounding the house, even if slightly off their home lot. Just now, however, I found the mare a very long way off. Her foal was closer to home, but still much further than either has traveled alone before. They seemed like they might be "stuck" on hillsides. I gave them a few hours, but when it came time for horse chores for the day, I sent them home and they came without trouble. Would they eventually come home on their own? I hadn't fenced the yard because I hadn't thought it necessary, but is it?