Stretched out, twisted and contorted, or curled into a ball, cats have mastered the art of sleep. As an homage, the word catnap formally entered the English language in the 1800s. Some people have the notion that cats are lazy layabouts sleeping the day away. It’s time to hit the snooze button on that misperception. Cats are the embodiment of the perfect predator, following a pattern of hunt, eat, and sleep. Sleep is an intrinsic, beneficial facet in the elegant feline design.
Catnap Connoisseurs
In a paper studying animal sleep times, adult cats averaged 10 to 13 hours of sleep a day, which equals about two-thirds of their life. Just as sleep requirements vary in humans, some cats may sleep more, close to 20 hours, while others sleep less. Predators without natural enemies have the luxury of long periods of sleep. Carnivores expend greater amounts of energy than omnivores or herbivores searching for food. As true carnivores with nutritional requirements of animal protein, cats need bursts of energy to hunt and catch prey. The energy bursts are like sprints or high intensity interval training, which cannot be sustained for long periods. Cats burn mega calories whether in the hunt for prey or toys. Sleep restores their energy needs.
Not only do cats make efficient use of their waking time, they’re also flexible with their waking hours. We often think of cats as solely crepuscular, awake during dawn and dusk since that’s when their natural prey is most active. However, research shows that this may not be hard-wired feline code but, rather, cats adapting their sleep/wake cycles to match their environment. Outdoor, free-roaming cats adapt their activity level to match that of their prey availability around the clock. Indoor cats tend to mirror the activity levels of their household, so if the lifestyle is active, our cats typically are also up and active too.
Kittens grow during their sleep, therefore need more sleep than adults. A kitten’s nervous system isn’t fully developed at birth and during the first three weeks of life a kitten sleeps 90 percent of the time. The mother licks them awake when it’s time to nurse. Over the next few weeks kittens sleep less but the body is still hard at work growing and developing.
In addition to the length of sleep kittens require, quality of sleep is also important. When stressed, hormones are released that could disturb natural hormone balance and growth. A stressful environment could impair what would otherwise be healthy growth and development. As adorable and playful as kittens are, it’s important to teach children not to wake sleeping kittens for extra playtime.
Sleep Mechanisms
Although humans and cats have different sleep-wake cycles–our average eight hours, typically overnight, to their nearly double amount of shut-eye during the day–we do share similar sleep stages, drifting into light sleep then deep sleep and back to light sleep. The amount of time cats spend in sleep cycles is shorter. Studies using an electroencephalogram (EEG), a test that measures brain activity during sleep, shows that humans and cats experience REM (rapid eye movement) and nonREM sleep.
While awake, a cat’s brain activity is displayed as clusters of sharp, irregular peaks on an EEG graph. As a cat slips into a light, slow-wave, nonREM sleep, the waves become long and irregular. This sleep phase lasts an average of 25 minutes. You may see your cat sitting upright while snoozing. His muscles are active and so are his senses; he’s ready to bolt out of the Buddha-like meditative state to chase prey or escape danger.
Moving into a deeper sleep phase, his muscles below the neck relax and he tends to roll over onto his side. During REM sleep the EEG shows rapid, erratic brain wave activity similar to the waking pattern. REM activity includes fast, irregular breathing and fluctuating heart rates. Eyes make bursts of jerky movements under the lids both horizontally and vertically. There are between eight and 30 movements per burst. This is when you may notice twitching whiskers, tail flicks, paw movement, and perhaps snoring. REM sleep is when humans dream and the same is theorized for cats, although we can only guess about their dream content. This phase lasts only about five to seven minutes and cats are slow to wake from this deep sleep. Cats flow back to a light sleep and cycle through the two phases until they’re ready to get up. For the first month of life, kittens fall straight into the deep REM sleep state.
Cats and Sleep Science
William Dement, “The Father of Sleep Medicine,” discovered REM sleep in cats in 1958. Independently, French physiologist, Michel Jouvet, realized he’d seen the same behavior in his sleep research with cats. Jouvet called it “paradoxical” (meaning strange or contradictory), because in this deep sleep phase animals showed behaviors similar to an awake animal. Jouvet observed in a 24-hour period cats were in one of three states: 35 percent in “wakefulness,” 50 percent light sleep, and 15 percent in paradoxical sleep. It’s interesting that sleep studies of cats jolted the “Golden Age” of sleep research in the 1950s and 1960s.
Sleep Concerns
The amount of time cats sleep varies by individual and age. Kittens and seniors tend to sleep more. Note, however, cats feign sleep when stressed. Feigning sleep is defined as “giving the false appearance of sleep.” In this state, the cat is anything but relaxed. The body is tense, the tail wrapped tight and close to the body, with paws tucked underneath. Ears are typically upright and slightly forward, listening to every sound. Eyes may be open or closed but the cat is keenly aware of the surroundings. Feigning sleep signals high levels of fear, anxiety, and stress (FAS) and is more often seen in shelter settings.
If you notice your cat feigning sleep, make sure you’re meeting his needs by providing the five pillars of healthy feline environment: a safe place; multiple and separated key environmental resources: food, water, toileting areas, scratching areas, play areas, and resting or sleeping areas; opportunities for play and predatory behavior; positive, consistent, and predictable human-cat social interaction; and an environment that respects the importance of the cat’s sense of smell.
A change in your cat’s sleep pattern could indicate illness. A shift toward more sleep could be almost any medical condition in adult cats since that’s when many chronic conditions, such as kidney disease, heart disease, and diabetes, start developing.
Conversely, if your cat has more energy and is sleeping less than usual, it could signal hyperthyroidism, hypertension, feline immunodeficiency virus (FIV), or feline cognitive dysfunction syndrome (CDS).
Consult your veterinarian if you notice a change in your cat’s normal sleep habits–either an increase or decrease–so any potential health issue can be treated early.
This article was reviewed/edited by board-certified veterinary behaviorist Dr. Kenneth Martin and/or veterinary technician specialist in behavior Debbie Martin, LVT.
