A single coyote's howl measures around 90 decibels--about as loud as a gas-powered lawn mower. That's pretty noisy, but when a pack of coyotes howl together they can sound louder than the sum of their individual parts Coyotes can change the sounds they make by altering the pitch of their voice and the loudness of their howling. By playing with sound in this way, one small family of coyotes can make itself seem bigger and tougher than it is, which...