In case you’ve ever wondered why dogs get up in the middle of the night and bark it is because, unlike humans, dogs and other animals do not have a day-night rhythm. Humans have a prolonged sleep of about eight hours each night but dogs have a number of naps throughout each 24 hour cycle. Some people refer to this as being polysomnic or polycyclic. A dog’s day is divided between a burst of activity, a snooze and then another burst of activity.
