When a cat walks past a mirror it often looks calm and proud. Some cats will even stop for a second and admire their own reflection. It almost feels like they believe the mirror is part of their world ...

DEAR JOAN: About a year ago, we had a full length mirror installed on the inside of our bedroom closet door. Whenever our cat, Frida, sees that the door is opened, she starts hissing and growling at ...

Animal play is fun, fair, chaotic, and serious business. The many ways in which nonhuman animals (animals) play with one another continues to intrigue many people—researchers, citizen scientists, and ...

Inspired by a reader’s claim his cat possibly possesses theory of mind, I decided to test my own pet (Letters, 25 January). The experiment: I stand in front of a (full-length) mirror with Samson, a ...