- Flehmen response: This is a facial expression in which the horse curls its upper lip and exposes its nostrils. It's a way for horses to detect and evaluate scents, and it's often associated with sexual arousal.
- Mounting behavior: A mare in heat may allow other horses to mount her, even if she's not receptive to breeding. This behavior is a way for the mare to signal her readiness and attract potential mates.
- Tail raising: Mares in heat may raise their tails when approached by a stallion. This is a physical sign of receptiveness and invitation to mate.
- Pinning ears: Some mares may pin their ears when approached by a stallion. This can indicate that they're receptive and ready for breeding, although it can also be a sign of aggression or defensiveness, so it's important to consider other body language cues as well.
- Frequent urination: Mares in heat may urinate more frequently as a way to release pheromones and attract stallions.