Why do cats love sunlight?

Any human who lives with a cat or two is bound to have noticed the special connection between cats and sunlight. Often, our feline friends look both majestic and relaxed when basking in the sun. They will also perform strange acrobatics and yoga-like stretches to fit into small sunny spots and will even move with their chosen ray of sunlight, adjusting their position or sleeping spot as the sun travels across the sky. But where does this love of sunlight come from?

The first reason has to do with cat biology. Cats have a higher body temperature than humans, averaging around 102°F. Maintaining such a high temperature is hard work for the body, so nature has given the cat a convenient shortcut: the desire for a warm sleeping spot. If a cat can find a spot in the sun, on top of a radiator, or in a cozy cat bed, these external heat sources help the cat’s body preserve the energy it would otherwise have to spend generating the necessary heat. So, seeking out warmth is a survival mechanism genetically programmed into the cat.

The second reason is tied to cat stress levels. A warm sleeping spot gives the cat an added sense of security. They instinctively know they are more vulnerable when sleeping and famously have an eye open and an ear on alert during most of their napping time. This is to avoid predator attacks. However, the increased vulnerability also comes from the slight drop in body temperature a cat experiences when sleeping. While asleep, a cat’s metabolism slows down, but choosing a warm spot to nap makes up for this loss in energy, which, in turn, gives the cat one less thing to worry about, thereby reducing stress and ensuring a more restful nap.

The third reason is rooted in cat history. Before cats decided to move in with humans, they lived in hot, desert areas. These living conditions are still reflected genetically in a heat tolerance that is much higher than that of humans. Our skin starts to feel pain around 113°F, while cats may be comfortable with temperatures as high as 125°F, explaining why our feline friends will stay in the sun on hot summer days, while we seek relief in front of our fans or air conditioners. Sensitivity to cold can vary slightly by breed. Siamese cats, for instance, often require more heat, whereas certain long-haired breeds may require less.

In addition to the black color gene, many black or tuxedo cats are born with the gene for the tabby stripes. It means their coat has an underlying tabby pattern that is mostly invisible – unless you catch them while they sleep in the sun. Intense sunlight breaks down the black pigment in the fur, causing the hidden tabby pattern to appear. In other words, black cats don’t just stay warm in a sunny spot, they undergo a magical color transformation!