It was the middle of a triple-digit heat wave in the hottest July ever recorded in Bakersfield, California. Bat biologist Erika Noel stepped beneath a freeway overpass along State Route 178, and the air felt like an oven. Forty feet above, clustered among five joints of the bridge, were thousands of Mexican free-tailed bats emitting their trademark musk—an odor laced with the smell of ammonia and corn chips.
