Domestic cats do this because they are not nocturnal (awake at night) diurnal (awake during the day) but crepuscular – most active at dusk and dawn. Crepuscular comes from the Latin word for twilight, crepusculum. Their hunting instincts kick in at these odd hours leading to those annoyingly familiar 4am crazies. And also to us cat owners being woken for food at the most ungodly hour of the morning – usually just as the sun is about to rise.
Some more useless information.
- There are subdivisions of diurnal animals – matutinal animals are most active in the morning, while vespertine animals are most active in the afternoon.
- Animals who sleep during cold months hibernate, while animals who sleep during hot and very dry weather estivate. This is known as hibernation and estivation