Why do horses grin?

It can be easy to assume that a horse baring its teeth is threatening to bite, and while this can sometimes be true, often there’s a much happier reason.

If you see a horse with their head up and back, and their lip curled, they genuinely look as though they’re laughing, especially when the head is nodding ‘ho, ho, ho!’. But this is something known as the Flehmen Response. And the response is to smell. They may be smelling a new horse on the yard, sensing treats in a pocket, or even just smelling the flowers. Stallions will do it to check if nearby mares are in heat.

When teeth-baring is a sign of aggression there are usually other clear signs. The ears may be back, they may have been startled by a strange horse, or be reacting to another horse invading their space.

We’re pretty sure that Marcus was happily sniffing the air in this photo. Maybe Verity was wearing a specially intoxicating perfume that day?