"You never heard of the burrowing nighttime desert frog?" He asked.

She glanced at him blankly. "No. I didn't think frogs could live in the desert".

He nodded. "They live on little drops of dew that collect on cacti during the night". As he gazed distractedly off into the distance, it seemed as if he was looking for something. His eyes flitted over the darkening landscape, taking in every contour and feature: cacti pointing up into the blazing desert sunset, sage and creosote bush feathering the edge of the horizon. "And they use their long and very colorful tongues to drink nectar from cactus flowers," He continued. "But they can be very dangerous. They have a special spot just behind each eye. It's like a bizarrely specialized kind of a tympanic membrane." He looked deep into her eyes. "It gives off an ultrasonic vibration that scrambles brains. That's how they kill their prey." As her eyes met his penetrating stare, she shivered. "And you never know what hit you, because the sound is above the human range. So you're just walking around in the desert, and all of a sudden, you just keel over dead. Just like that."