What benefit does a mirror provide for a lonely horse on stall rest?

A mirror can provide significant benefits for a lonely horse on stall rest, primarily by offering companionship. Horses are social animals that thrive on interaction with other horses. When placed in a stall alone, they can experience feelings of boredom, loneliness, and anxiety. A mirror can simulate the presence of another horse, making the horse feel less isolated. This reflection can encourage social behaviors, allowing the horse to interact with its "companion," which can enhance its sense of well-being.

Additionally, while the other options also have merit, the most direct and immediate benefit of a mirror in this context is the companionship it offers. Horses may engage in behaviors such as grooming their reflection, which can help ease their sense of loneliness. Distraction and anxiety reduction can be indirect benefits resulting from improved emotional states due to the sense of interaction provided by the mirror. Therefore, the focus on companionship as the core benefit emphasizes the social needs of horses and the role that mirrors can play in fulfilling those needs when direct contact with other horses isn’t feasible.