Ask Dr. Universe

Dr. Universe: Asked by Izzy, age 10, from Maryland.

Dear Izzy,

Not only do I enjoy answering science questions from kids, but I also like naps, tuna fish sandwiches and chasing lasers. I wasn’t entirely sure why I like chasing those little red dots. I asked my friend Leticia Fanucchi, a veterinarian at Washington State University.

“Cats like lasers because they are predators and like to chase or hunt anything that moves fast around them,” Fanucchi said.

A zipping red light that quickly switches directions might have a similar motion to a mouse or other critter. The light sort of mimics an animal scurrying around to escape its prey. Even though we cats know the laser is not an actual mouse, it triggers our predatory instinct.

An instinct is something hard-wired into animals – they don’t have to learn it; they just naturally know how to do it. For example, dogs drool when they see food. Birds build nests. These are all instincts, and some can help animals survive.

As predators, cats also have a few other tools that are useful for survival: claws and sharp teeth. We also have good eyesight and hearing. Plus, we are pretty fast.

The house cat is actually descended from a wild species of cat, including the European and African Wild Cat. These cats were big hunters. While house cats are more domesticated, we still share that instinct to hunt.

Meanwhile, big cats like lions, tigers and cheetahs have even bigger claws, teeth and speed. Some of these animals show at least a bit of interest in laser pointers, too.

It turns out cats big and small aren’t the only ones who like to chase lasers. Other animals seem to be very curious about them. Dogs will chase lasers. Some insects go a little wild when they notice a laser moving. People have even recorded fish following the light in aquariums.

Biologists might call the laser a kind of superstimuli. It really draws in the animal’s attention because it’s so different from anything else going on in its environment. Unlike smart prey in nature who camouflage, the red laser point stands out.

While investigating all kinds of things about cats and lasers, I discovered that house cats haven’t been playing with lasers very long. The first cats were domesticated about 4,000 years ago in ancient Egypt. Some researchers think we might have been domesticated even earlier.

Lasers were only invented about 60 years ago. That might seem like a long time at first, but when you consider how long cats have been domesticated, only a small number of cats throughout history have ever played with a laser. That got me wondering how lasers work in the first place. We’ll save that question for another time.

Sincerely,

Dr. Universe