Sleeping Horses Horses do have a unique ability to be able to stand up and sleep (I wish I could take a nap standing up lol). However they also do require to be able to lie down and sleep. Horses will lay down either flat out, or up on their side with their chin resting on the ground. This will only happen if the horse feels completely safe, as they are prey animals and a sleeping prey animal is a very easy target for a predator (even though we don’t have any in Australia). Quite a lot of mine will often get their deep sleep during the day when they are with the other horses and feel safe and relaxed. So if you do see a horse lying down they are most likely just taking a nap.