Barn Buddies

Horses have a herd hierarchy and within that hierarchy, they make individual friendships, often with a horse close to them in the herd order.

At Tim's they're also paired up by gender, too.

 Hokey and Trouble are buddies. Trouble usually decides where they will walk or hang out, but Hokey is really the boss.

 Diablo is the herd alpha, and Abby is her best friend. However, if Diablo is not by her side, Trouble and some of the others can push Abby around.

So, she wisely stays close to her BFF!