When a wiggly little bead of light catches a dog's eye, nothing in the world matters more than capturing it. Unfortunately, "it" is just an ungraspable bundle of massless photons. The lack of closure in laser-beam chasing could be messing with your dog's head.
Dogs (and some cats) instinctively chase these bright-red dots simply because the dots move, said Nicholas Dodman, a professor of animal behavior at Tufts University's Cummings School of Veterinary Medicine. Movement automatically stimulates their innate prey drive
, which explains why lower-on-the-food-chain animals such as rodents and rabbits often freeze in place as a survival strategy. Although dogs aren't so discerning when it comes to color
, their eyes contain a high preponderance of light-sensitive cells called rods for top-notch motion detection.
A laser beam's incessant movement keys into this predatory system. "They can't help themselves; they are obliged to chase it," Dodman told Life's Little Mysteries.