My old black mare lived out 24/7 with a younger gelding, who was continually pestering her, keeping her on the move around the field. He didn't ever get particularly close to her, but whatever vibes he was giving off meant that she spent quite a large part of each day walking around the field, with the occasional trot and sometimes even a sharp turn as she spun quickly in the opposite direction. I used to feel a bit sorry for her, until the gelding was on box rest for a week. The increase in her level of stiffness when she was in the field on her own was dramatic, and by the end of the week she was walking gingerly down the slope to meet me, rather than her usual enthusiastic trot. It was a great lesson in how keeping active, whilst sometimes seeming like hard work, is so important in the health of the older horse.