Resting behaviour varies with age, with adult horses resting for periods of between 7 and 8 hours a day (Kurtz et al. 1982/1983). Depending on fatigue level, location and age, horses rest in the following ways:

• Dozing standing up, alternately resting on one hindlimb
• Lying on the chest with legs tucked in
• Lying flat on the side; this form of resting is only observed in the security of the herd or in familiar stable surroundings

While sleeping lying down, horses (particularly foals) sometimes whinny or squeal and even running movements are occasionally observed. This suggests that they can dream.

In the first few months of life, foals spend most of their time at rest; a third of it lying down. It is believed that sleep is associated with consolidation of learning. Resting time decreases markedly from the age of 3 months (McGreevy et al. 2004).