Radroaches are usually found in underground areas and sewers across North America, which can cause them to be a pest in certain Vaults, where they can often be found in fairly large groups. Radroaches feed on dead organisms, but they will attack living creatures if isolated. Their numbers are their greatest advantage. Radroaches live mostly in the areas east of California. It is said that radroach innards are useful in the treatment of radiation poisoning, and are widely used by tribals for this purpose.