Lawrence, a newsletter subscriber, recently emailed me this question:
At night when I am in bed and a cricket starts chirping in another room, I can very lightly put a foot on the floor getting out of bed. Instantly the cricket will go quiet. Are they that sensitive to floor vibration, noise or?"
I know what you mean, Lawrence! Last summer, I was trying to collect some crickets for a program I was presenting at a local library. The crickets were chirping loudly underneath a piece of black plastic I had put down to solarize some weeds in a landscape bed. I figured they would be an easy catch. But every time I came close to the plastic, they went silent!
Noise really is nothing more than vibrations traveling through the air and reaching our ears. In essence, noise and vibration are the same thing.
Crickets don't have ears like we do. Instead, they have a pair of tympanal organs on their legs, which vibrate in response to vibrating air molecules (sound) in the surrounding air. A special receptor called the chordatal organ translates the vibration from the tympanal organ into a nerve impulse, which reaches the cricket's brain.
The cricket, ever on the alert for predators, responds to this message by doing what it can to hide – it goes silent. Crickets are extremely sensitive to vibration, so I'm not surprised that it reacts to your movements, however softly you try to get out of bed and sneak up on it.
Only male crickets chirp, by the way. The males make that chirping sound by rubbing the edges of their forewings together. They chirp to call for female mates. Since most predators are active during daylight hours, crickets chirp at night.
If you're patient, though, you can sneak up on a chirping cricket. Each time you move, it will stop chirping. If you remain very still, eventually it will decide it's safe, and begin calling again. Keep following the sound, stopping each time it goes silent, and you'll find your cricket.