This is a common myth that is not exactly true. It is easy to see how it started, though. Cockroaches are one of the hardiest and most adaptable animal species on the planet. They can survive indefinitely in situations that would kill a person. However, neither cockroaches nor any other living species can survive the blast zone of a nuclear explosion. Cockroaches caught in a nuclear blast would be incinerated to dust like everything else.
The thing about a nuclear explosion, though, is that most of the death toll is racked up in what follows after the blast. Anything not caught in the blast will be exposed to high levels of radiation that will continue to be present as fallout, radioactive ash, rains down upon the region. Cockroaches are much more resistant than humans to radiation. Cockroaches can live through up to 105,000 rem of radiation, while humans can’t make it past 800 rem for longer than 14 days. The longest a person has survived exposure to 10,000 rem or higher was in an accident in Rhode Island in 1964. The man only lived for 36 hours after exposure.
The next problem after a nuclear blast is a lack of food. Cockroaches will eat almost anything. They have no hang-ups about cannibalism and will gladly eat other cockroaches, if necessary. Humans can eat a variety of organic materials as well, but not quite as much as the cockroach. Cockroaches are also good at finding shelter.
It is estimated cockroaches have been on the Earth for 340 million years. That was millions of years before the dinosaurs even appeared, and millions more after they dinosaurs died out. Modern humans have only been around for 200,000 years. That means cockroaches have been here 1,700 times longer than humans. That time has given them some great practice in the arts of survival.
Posted 2056 day ago