ANNA LEMIND: “Your Cat Can See Things That Are Invisible To You”

Cats are considered by many as symbols of mysticism because of their elegant and flexible body, as well as their gaze that can “magnetize” anyone…

Indeed, as recent scientific data show, there is another reason why cats have a title of ‘mysterious’ creatures. It’s all because cats see things we cannot see with our eyes!

Cats, like some other animals, have the ability to see psychedelic stripes on flowers or fancy patterns on the wings of birds, which are invisible to human vision.

The secret behind the super vision of our four-legged friends is the UV light. According to a recent study cats, as well as dogs and other animals, can perceive this type of light which humans can’t.

“There are plenty of things that reflect UV radiation, which some sensitive animals are able to see, while we are not,” said Ronald Douglas, professor of biology of the City University of London and co-author of the study. “For example, these may be certain patterns on flowers that show where the nectar is, or traces of urine of an animal. Also, reindeer can and see polar bears as the snow reflects UV radiation, while white fur does not.”

Therefore, cats, dogs and reindeer can detect with their eyes animals with white fur, while most people will only see… white snow.

Douglas, who specializes in optics, and Glen Jeffery, professor of neuroscience of the University College London, argue that cats, dogs, hedgehogs, rodents, bats, weasels and the okapis can detect significant levels of ultraviolet radiation.

“For decades, we have known that many invertebrates such as bees see ultraviolet light,” continued Douglas, saying that even birds, fish and some reptiles were recently added to the same list.

“However, scientists believed that most mammals cannot see ultraviolet light because they have no visual pigment with maximum sensitivity to ultraviolet light, but instead have lenses like those of humans, preventing ultraviolet light from penetrating into the retina,” he said.

The professor explained that the visual pigments are those that absorb light and turn it into electrical activity, which, in turn, is transmitted through nerve cells. It seems that it is not always necessary for sensitivity to ultraviolet radiation. Instead, transparent parts of the eye such as the cornea and the crystalline lens in some animals transmit wavelengths of ultraviolet light.

This ability allows more light to pass to the retina, “something that would be very useful for a nocturnal cat“, he continued.

It could also explain why cats show so much interest to ordinary objects, such as a piece of paper. Sometimes chemical substances are added to paper, textiles, laundry detergents, shampoos and cosmetics in order to make objects look brighter. Once these optical brighteners absorb the ultraviolet light, they may look differently in the eyes of animals that are sensitive to UV rays.

Some people, for example, those who have undergone cataract surgery, also can see some of the UV light, but most cannot.

“We all know that ultraviolet radiation can be harmful,” said Jeffery in Discovery News. “I work a lot in the Arctic, where the UV radiation levels are too high as there is much snow and ice. The surfaces reflect 90% of UV radiation, with the result that animals are exposed to it. If you do not wear goggles, your eyes will hurt within the first 15 minutes.”

However, studies on reindeer have shown that repeated exposure to ultraviolet light does not bother them at all.

It is possible that cats, deer and some other animals that can detect UV rays have a protective mechanism. Also, scientists believe that UV light tends to create more blur.

“Humans are good at one thing: they can see more details,” added Douglas and concluded:

“Maybe that’s why we have a lens that ‘blocks’ ultraviolet light. If you do not have it, the world might appear more blurred.”




JANE MEGGITT: “Ways Cats Understand Physics”

Flying or jumping kitten cat isolated on white

Of course, if you play with your cat, you already know he understands string theory…

The Kyoko University study may win an award for the most adorable science project ever, as much of it consists of videotaped cat reactions. While the study proved that cats have an elemental understanding of physics and cause and effect, it also showed that cats score well in the common sense department. It’s not easy to fool a cat… unless you’re using a laser toy.

The experiment

Researchers showed 30 cats “either an object dropping out of an opaque container” or nothing dropping out when the containers were turned over. First, scientists shook the containers with objects to produce a rattling sound, but also shook the empty containers which didn’t produce noise. The felines then were allowed to roam around and explore the area where the experiment was conducted. Fifteen — or half — of the cats “actively explored” containers with an object that made noise in them. Just 10 cats explored the “no object and no sound” containers.

The results showed that cats looked at the container longer when there was noise than when there wasn’t — an action known as “preferential looking.” They also peered longer when an “incongruent” event occurred — such as an object dropping out of a container that didn’t make a noise, or no object dropping out of one that did rattle.

The researchers concluded the result “suggests that cats inferred the existence (or absence) of the object based on the rattling sound (or no sound) and predicted the appearance of the object (or not), applying a physical rule.” They surmised this reflects natural feline hunting ability, as they must often discover the location of prey solely by sound. Since cats are basically nocturnal — although as any cat lover knows, they sleep day and night — their primary hunting hours are spent in the dark. The study shows cats use cause and logic regarding noise to determine the presence of invisible objects.

Feline hearing

Dogs have a fantastic sense of smell, but felines possess exceptional hearing ability and beat the canines in the aural department. Although cats have good vision, hearing is their sharper sense. A typical feline’s audible range is 79 kilohertz, or about 10.5 octaves. Human hearing is in the 20 kilohertz range. That means a cat can distinguish the very high-pitched sounds made by rodents, inaudible to the human ear. He can tell the difference between similar ultrasonic sounds several yards away.

Feline ears have 22 muscles in the outer ear, or pinna. Consisting of cartilage and covered with hair, the pinna is designed to catch sound waves, sending them down the ear canal to the eardrum. You’ve certainly noticed that your cat can move his ears separately, and often communicates his emotional state via the ears.


Does this mean a deaf or hard-of-hearing cat can’t hunt? Not necessarily, although he’s unlikely to perform this task well. In an area where prey is abundant, the deaf cat may still catch mice or other animals. It also depends on prey drive — there are some cats that really enjoy hunting and will pursue it enthusiastically even if they aren’t particularly successful. Of course, deaf cats really belong indoors, as the outside world is too dangerous for them.

Do try this at home

The Kyoto University experiment is one that you can try to replicate at home with your own kitties. The Kyoto University team used metal balls as items in the opaque containers. You can use anything that rattles, but consider expanding the experiment. Along with ordinary rattling items, switch to toy mice or similar objects resembling prey.  See if your cats show more interest in prey-like pieces than other noisy articles.

In simple terms, cats understand an action leads to a reaction. Researchers still don’t know “what cats see in their mind’s eye when they pick up noises,” so further study is necessary.

—Jane Meggitt