Cockroaches are not radiation-proof and most are not pests
Few animals have a worse reputation than the humble cockroach, but almost everything we think we know about them is an urban myth
Reputation: Yuck. Cockroaches are filthy, immortal scavengers that are unaffected by radiation. In a post-apocalyptic world, it will be these dirty little critters that survive.
We would be better…
Source: BBC – Earth – Cockroaches are not radiation-proof and most are not pests