Why do cockroaches run away when you turn on a light?
Show answer & explanation
Answer: Darkness hides them from predators
Light hurts their sensitive eyes — Light doesn't damage a cockroach's eyes; they're sensitive enough to see in dim light, but a lamp doesn't hurt them. They run because light means exposure, not pain.
Light dries out their bodies within seconds — A few seconds of room light won't dry out a cockroach; its waxy outer shell holds water in. Running from light is about hiding from predators.
Darkness hides them from predators ✓ — Cockroaches are active at night, when birds, lizards and other hunters can't easily spot them. Fleeing light is an inborn reflex that keeps them hidden, which is why they scatter for the nearest crack when a kitchen light switches on.
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