JAPAN
JAPAN — Cats leave smells to tell other cats they were there. Scientists in Japan finally know how it works. A cat's kidneys store 13 kinds of fatty acid, and those acids end up in the cat's pee. Every cat has its own mix, so the smell is like a name tag. Lions and tigers do the same thing.
Why it matters: If you have a cat, it is leaving notes for other cats every single day.
MORIOKA, JAPAN
MORIOKA, JAPAN — For more than a hundred years, scientists wondered why cat kidneys are packed with blobs of fat. Now they know. The blobs store 13 special fatty acids that end up in a cat's urine. Every cat has its own mix, and the mix stays the same over time. That turns a cat's mark into a chemical name tag other cats can read for at least a day. Masao Miyazaki led the work at Iwate University in Japan. His team found similar chemicals in lions, tigers, and leopards. Nobody has proven yet that wild cats use them to tell each other apart.
Why it matters: Your cat is not being gross when it marks the house. It is signing its name.
Sources: Current Biology, Japan Times, Science
Published in Sunday, August 23, 2026 edition.