The urine a dog leaves behind is like a smell fingerprint. It’s full of chemical messages like hormones. One whiff of another dog’s urine tells my dog roommate important stuff—like the other dog’s age, sex and health information.

Keeping your goldfish on a regular light/dark schedule will make it happy and healthy. But feeding it at the same time every day may help even more.

The QWERTY keyboard hit the market as early as 1872. It was part of a new device called a typewriter. But nobody is sure why inventor Christopher Sholes organized the keyboard that way.

Watching TV up close won’t hurt your eyes. But your eyes need to focus on close things and far away things. That variety keeps yours eyes working.

Air moves because the sun heats Earth unevenly. Warmer air rises and cooler air sinks. Air molecules flow from places with lots of air molecules to places with fewer—as wind.

Peng told me that self-driving cars are getting safer. Some studies show that certain driverless cars have fewer crashes than cars driven by people in similar places.

Taking care of butterflies—and other beneficial insects—is one way to make the world a better place. And butterfly lovers in the Pacific Northwest may be in a good position to help our fluttery neighbors.

Wolf biology made them good candidates to live with humans. That includes their social structure and physical needs. Bear biology doesn’t work the same way.

Tastes are chemical signals. They’re picked up by gustatory (taste) receptors in some of the butterfly’s cells.

We see a planet’s color because of the way our eyes and brains process the sun’s light as it reflects off that planet. How it looks depends on the planet’s state and composition.