Do Cockroaches See Where They Are Going?
Millions suffer from a condition known as CSDS, or cockroach stare-down syndrome. A typical victim wanders in the kitchen late at night searching for a ham sandwich or other food supplies. Upon switching on the light, a cockroach materializes on the counter. The person and pest both freeze. The roach wags its antennae and stares at the person, and the person stares at the roach. Both tremble as time slows to a standstill. Typically, the cockroach executes the first move and makes a break for it. The hungry householder is left with CSDS.
Actually, there’s no such thing as CSDS because cockroaches see you long before you see them. Odds are they’re already heading for the hills by the time you switch on the light. You think you have good eyes because each one has a single lens? The tiny cockroach eye has more than 2,000 individual lenses. These compound lenses allow the critter to detect motion at a 360° sweep around its entire body. That’s why you can’t sneak up on a roach from behind.
Additionally, light-sensitive cells in cockroach eyes, called photoreceptors, allow the critter to see in near total darkness. Scientists have determined roach eyes can absorb one photon of light every 10 seconds. The eyes and brain work together to pool the light signals over time, like time-lapse photography.
However, cockroach eyes are not infallible, thank goodness. Cockroaches cannot see well in red light. So if you want to sneak up on a roach, install red lights throughout your house. Your neighbors might think you’re weird but you’ll be able swat those pesky critters a little easier.
Roaches are equipped with other sensors that keep them ahead of predators. The little hairs on their little legs can detect motion and their wagging antennae allow them to “smell” food. And the antennae of male roaches are fine-tuned to detect females.