Domestic cat asleep (photo from Wikimedia Commons)

26 September 2025

Today I’m taking a break from outdoor stuff to look at an indoor mammal and sleep cycles.

Unlike our society, where humans are expected to have one long sleep period per day(*), cats sleep many times a day in periods lasting 50-113 minutes. They often sleep while we’re awake and wake while we’re asleep. What do they do when we’re not watching?

(video is faster than real time)

When the humans sleep.. ? pic.twitter.com/RwaTW9M6KX

Familiarity can breed contempt. This video shows two cats in a dominance face-off — notice their ears! The dominant (black) cat is busy intimidating his fellow cat and wants no interruptions from the robot. With one gesture he sends it away.

(*) More information on sleep cycles:

• Cat sleep cycles are called polyphasic sleep — many phases per day.
• Monophasic sleep (just one long sleep bout) is expected of adults in our society.
• Other societies expect a daily nap or siesta (biphasic sleep). In Japan and China, these nations view napping at work as an expected norm and something that is beneficial.
• Wikipedia explains: Polyphasic sleep is common in many animals, and is believed to be the ancestral sleep state for mammals, although simians (our branch of primates) are monophasic.