Are cats nocturnal? It's a valid question, considering your cat likely zooms around your darkened house — and maybe even demands at least one late-night snack — between the popular feline happy hour of 3:00 a.m. and 4:00 a.m.
Despite your kitty's disrespect for your sleep schedule, she's not actually nocturnal: she's crepuscular. This biological category describes animals whose peak hours of activity occur at dawn and dusk, explained Mother Nature Network. Many crepuscular animals, from prey like rabbits to predators like lions, evolved to take advantage of times when temperatures were the coolest in their desert habitats.
Understanding the typical pattern of crepuscular behavior — brief bursts of energy tempered by an extended period of rest — may help you see why your kitty is most playful at precisely the same time that you are ready to wind down.
Crepuscular Animals
Truly nocturnal animals, such as raccoons and owls, roam around throughout the night — taking advantage of the darkness to hunt their prey. Diurnal animals like squirrels, butterflies, and humans, on the other hand, work the day shift. But crepuscular animals take advantage of the receding daylight and darkness to capture the best of the daytime and nighttime worlds.
"The most quoted theory for crepuscular activity is that it offers an optimal balance," explained BBC Earth News. "There is just enough light to see, but it is dark enough to lower the odds of being caught and eaten." Predators like hawks have decreased vision during the twilight hours and, therefore, present less of a hazard to small, tasty crepuscular critters.
While this behavior is instinctive to each species, the structure of an animal's eyes plays a big part in whether they are nocturnal, diurnal, or crepuscular. Some crepuscular creatures — like your kitty — have slit-shaped retinas, as do nocturnal animals. (This explains why she easily can pounce on your toes in even the darkest room.)
"If you have a vertical slit, you're very likely to be an ambush predator," said Martin Banks, a vision scientist, to National Public Radio (NPR). The vertical slit has "optical features that make it ideal" for critters like your cat to lie in wait (for long periods of time) before pouncing on their prey. You'll often see your kitty display this type of play behavior at dusk or dawn — or perhaps when you're trying to get some shut-eye.
To Sleep or Not to Sleep
Although they are biologically wired to be most active during twilight, some cats carry their exuberant behavior into the wee morning hours. After all, it's not as if they're perky from sleeping sixteen hours in a row. Most cats wake their pet parents up from a deep sleep at least once per night — a habit that can drive their humans batty. It's no fun to walk around sleep-deprived. (This pattern of nighttime antics typically prompts the "Are cats nocturnal?" question.)
This is where a cat's sleeping pattern comes into play. Sleeping (and restful dreaming) for cats is not the same as for their human family members, explained Animal Planet. Cats "do experience both non-REM and REM sleep, but for cats, 'asleep' is not 'off the clock.' Cats are always on the alert, even when they're dozing. If a strange noise wakes them up, they're almost instantly aware and fully operational. It's an ability that cats (and wild animals in general) depend on to stay safe, and fed, in [nature]." You may notice this in your own home when, say, your furry friend is in a seemingly deep sleep far away in the corner of the house but comes running at the sound of her cat food container being cracked open.
House cats don't depend on hunting for their source of food, but this doesn't mean those instincts are gone. As genetics professor, Dr. Wes Warren, told Smithsonian Magazine, "cats have retained their hunting skills, and they're less dependent on humans for their source of food." This is why your kitty will "hunt" her toys, kibble, and cat treats. Her hunting instincts are intrinsically connected with her crepuscular nature, resulting in a fascinating form of indoor behavior that aligns with the behavior of her ancestors — it's like having your very own miniature lion.