Despite ruling the Internet, cats remain mysterious creatures.

A paradoxical blend of needy and aloof, cuddly and conspiratorial, one of the world’s most popular furry friends continues to delight and befuddle those of us (myself included) who live with them.

Gary Weitzman, a veterinarian and head of the San Diego Humane Society and SPCA, is used to answering cat questions. He got them all the time as the host of a call-in radio show about pets and their problems. (See "What Do Cats Think About Us? You May Be Surprised.")

So after writing How to Speak Dog for National Geographic Books, it seemed natural to follow it up with a feline version. The result is his new book, How to Speak Cat.

Where Your Cat Goes May Shock You A new study placed GPS tracking devices on house cats, and turned up some interesting findings. While most cats stay in the vicinity of their homes, others travel much farther away, to the surprise of their owners.

In honor of Big Cat Week, National Geographic recently talked to Weitzman about the crazy things that cats do. The interview has been lightly edited for length and clarity.

You’ve been a veterinarian for 25 years, so you’ve probably pretty much seen it all in terms of cat behavior. But was there anything new that you learned while writing the book?

There’s the basic kind of facts that I learned, like Guinness Book of World Record-type things, that I really didn’t know. [For example], the oldest living cat, [now deceased], was 27 years old out here in Point Loma, California. (Watch a video on why cats are so secretive.)

But I learned that scientists think that cats respond better to women, because women have higher-pitched voices than men. These facts are in bold print on every other page in the book, and nearly all of them surprised me.

Besides starring in YouTube videos, do cats have any other remarkable abilities that you learned about while writing this book?

Cats can see in the dark six times better than humans. That’s not something you learn in vet school, and you don’t learn that working in a shelter or working with animals for decades. But six times better than a person—that’s pretty impressive. (Also see "How Cats and People Grew to Love Each Other.")

A cat’s breed can certainly affect its appearance, but can it affect a cat’s personality?

Definitely. The color of coat is linked to behavior. For example, tortoiseshell cats, torties, can be independent and they usually like just one person, and they can be pushy about what they want. Torties and calicos and Abyssinians all have strong documented links between their coat color and personalities. More anecdotal is the orange tabby, who is the poster child for the most gregarious. But personality really seems to go with coat color.

When people ask you questions about their cat’s seemingly bizarre behavior, what are their most common issues?

One of the biggest questions I get is why does my cat become a psychotic rocket and suddenly go from 0 to 60 and zoom around the living room. We don’t really know for sure, but indoor cats especially have a lot of pent-up energy that they can’t exercise, whereas wild cats have hunting, stalking, and waiting on edge to keep them busy. It’s an energy release. That’s really what it is. The other question is why is my cat not using the litter box correctly, which is, not to be funny, the number one question I get. (See National Geographic readers' pictures of cats.)

Speaking of wild cats, how similar is our average house cat to its wild ancestors?

They’re very, very similar. Domestic cats have only been around for half the time that dogs have, so you can see almost the same behavior among lions, tigers, and leopards that you do among domestic cats. That is, perhaps, one of the biggest draws of these animals—we can live harmoniously with them and still get to watch Mutual of Omaha every day. They’re still part wild. They haven’t gone to finishing school yet. (See "Our Most Stunning Pictures of Big Cats.")

With so many big cat species endangered, can our love for domestic cats help save their wild cousins?

Look at the almost universal outrage over the death of Cecil the Lion this summer. People love cats. Cats, hands down, own the Internet. That’s the leverage that we have to try and stop some of the astonishingly bad practices towards the other cats on our planet.

Follow Carrie Arnold on Twitter.

Big Cat Week continues all this week.