Do horses sleep at night

No! Horses are awake during the day , although they sometimes take naps. But if there is more than one horse in a stable at night, while the other horses are sleeping, one will stay awake to be like a 'watch horse'!

Above is incorrect. Horses are both awake at night and during the day. In fact, horses only spend 3 out of 24 hours a day sleeping. Just 3 hours! Sometimes even less! So, technically, yes- horses are nocturnal, but also disturnal (awake in the day.)