Horned Desert Viper

The horned desert viper's ability to hunt at night has always puzzled biologists. Though it lies with its [blank] buried in the sand, it can strike with great precision as soon as prey appears. Now, young physicists Leo van Hemmen and Paul Friedel at the Technical University of Munich in Germany have developed a [blank] of the snake's auditory [blank] to explain how the snake "hears" its [blank] without really having the ears for it. Although the vipers have [blank] ears that can hear [blank] between 200 and 1000 hertz, it is not the sound of the mouse scurrying about that they are detecting. "The snakes don't have external [blank] ," says van Hemmen. "So unless the mouse wears boots and starts stamping, the snake won't hear it."