The Descent, a painting by Jesse Mockrin © The artist. Courtesy the artist and James Cohan, New York City

Rabbits are capable of digesting their teeth as they wear down and reusing the calcium to grow new ones. Chinese scientists successfully raised to adulthood mice born of two fathers and then dissected them. Mice who inhale xenon gas stave off dementia. Estrogen receptor 1–expressing neurons in Barrington’s nucleus were found to act as the master controller of mouse urination, and a survey of 1,328 urinary events found that, unlike contagious yawning, the contagious urination of…