Elegant, quick-witted and… sleepyheads! Yes, cats sleep a lot! And they apparently dream, just like we do. The image often portrayed of cats stretched out in the sun or curled up in front of a fire is not just a cliché. Dr. Maria Grazia Calore, a veterinary surgeon, and expert in pet behaviour explains why sleep is so important to our cats.
Between sleep and wakefulness
If you're at all sleep deprived, you may be envious to learn that cats sleep between 10 and 18 hours a day. However, as with humans, some cats are diehard couch potatoes, while others are energetic and sports. Needless to say, cats that are more stimulated (because they get to go outside or are provided with stimulation indoors) tend to sleep less than their less-stimulated counterparts.
But how are the hours and hours of sweet sleep that our domestic felines enjoy spent? It is known that cats have stages of sleep just like humans. In fact, the stages alternate between episodes of light sleep and phases of heavy sleep lasting about 20 minutes, followed by periods of around five minutes of REM (rapid eye movement) sleep.
REM sleep is the stage of sleep in which cats – like humans – dream: when their eyes move rapidly behind closed eyelids, and their ears, whiskers, paws and tails twitch vigorously as they act out their dreams.
Thanks to tests using an electroencephalogram, we know that cats tend to have a lighter sleep during the day. This semi-alert state mirrors the sleeping habits of the domestic cat’s wild cousins, where the cat is not only a predator but also potential prey, and to survive it must be on alert in case of danger.
What do they dream about?
For humans, REM sleep is thought to help the brain reorder by setting experiences to memory. It is therefore fair to assume that cats also relive their daily activities – such as hunting, playing, grooming and social interactions – in their dreams. And as man has to cope with the occasional nightmare, so, too, do our cats; their dreams likely peppered by imaginings of fight or flight situations, which often elicit inadvertent growls or mewing from their tiny mouths.
For cats, REM sleep is essential and if interrupted, can have severe repercussions. In fact, studies on sleep deprivation in humans and other animals confirm that lack of sleep can affect several essential behaviours, such as attention, cognitive abilities and moods.
So the moral of today’s story is: “Let sleeping dogs lie” – that is, don’t wake up dogs, cats or humans when they are sleeping because for each, it would be a spiteful and possibly dangerous thing to do.