The Wild File


Q) Why does tomato juice de-skunk my dog, whereas my guava-strawberry shampoo doesn't help at all?
Gillian Ashley, Gardiner, Maine

A) WE'LL GIVE MS. ASHLEY an A for aggressive trial and error, but the bad news is, her entire premise is flawed: Even tomato juice doesn't work as a skunk-spray deodorizer. Giving Fido a V-8 bath is no better than soaking Pepé Le Pew in $5 perfume—it will temporarily cover up the skunk's stinky calling card but do nothing to combat the source. To really quell the smell, says William Wood, a chemistry professor at California's Humboldt State University, try his mad scientist's blend of one quart hydrogen peroxide (the common 3 percent variety), one-fourth cup baking soda, and a teaspoon of liquid laundry detergent. This concoction will blitzkrieg the malodorous thiols—the skunk's offending chemical compounds, which contain rotten-egg-smelling sulfur—and through oxidation transform them into odorless sulfonic acids. Douse a sprayed dog with this recipe, rinse, and repeat until the odor disappears. It's harmless, but beware: Hydrogen peroxide has one side effect long embraced by Midwestern mallrats and SoCal surfers alike. "It's strong stuff," warns Wood. "It can turn a black Lab into a chocolate Lab."

Q) On a hiking trip in Yosemite, our reward was the roaring Nevada Falls. We sat and stared at the rush and soaked in the fine mist. But some five minutes later, when we finally looked away from the falls, the valley walls suddenly appeared to stretch like Play-Doh—not just to me, but to everyone in the group. Was it something in the water, or what?
Clay Carter, Sunset Beach, California

A) DON'T PANIC—sounds like you were simply experiencing "motion after-effect," aka the waterfall illusion. First noted by Aristotle around 350 b.c. and later documented in 1834 by English philosopher Robert Addams—who experienced the phenomenon while viewing a cascade in Foyers, Scotland—this psychedelic illusion occurs after prolonged viewing of any uniformly moving surface, be it a waterfall or a Tour de France peleton. The reason? Inside your gray matter are thousands of specialized brain cells that sense motion. Some of these neurons detect downward activity, some perceive left-to-right movement (or vice versa), and still others sense upward motion. When you focus on a waterfall, downward-sensing cortical neurons become overstimulated and fatigued, throwing your entire motion-detection system out of balance. Consequently, when you avert your gaze, the exceptionally vibrant remaining neurons go into overdrive, and stationary objects seem to scroll upward or stretch like a Salvador Dalí clock. But as you probably noted, there's no permanent effect—you can go ahead and stare at waterfalls as long as you like. The illusion, which can last anywhere from five to 30 seconds, subsides as soon as your downward neurons have had a chance to take a brief siesta.

Q)I heard that when bats exit their caves at night, they always turn to the left. Is this really true?
Steve Smith, West Conshocken, Pennsylvania

A) NEGATIVE, Batman. The nocturnal flying mammals often exit their caves flocking leftward, but that's by no means written in instinctual stone. Bats, which subsist on insects and fruit, are just like any fast-food-loving human—where they head to eat is determined by whims of their voracious appetites. "If they're looking for moths that hang out near the cotton fields, they'll make a beeline for the cotton fields," says Bob Benson, public information manager for Bat Conservation International, an Austin, Texas-based research facility that owns a cavern that's home to 20 million Mexican free-tailed bats. "The direction is determined by where their favorite foraging grounds are situated." But even though the direction isn't always left, it is predetermined. Usually a scout will venture from the cave early and return with a report on foraging conditions, delivered via ultrasonic vocalizations. After all, if every bat was driven randomly by its own palate, their mass exits could cause nightly 20-million-bat pileups.

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