Mole rats are mutated rodents that are much larger than their pre-War cousins. They have survived as a species by burrowing underground where the soil protected them from direct nuclear explosions. However, they still were massively mutated by the remaining fallout, increasing their size as well as their viciousness. Some people in the wastes have been known to train them and keep them as pets.
Mole rats are usually found in packs of roughly three to four, but are occasionally in pairs or by themselves. They are often witnessed standing on their hind legs and sniffing the air, allowing them to smell any predators that may be coming. They occasionally scratch at the ground, attempting to dig a burrow.
Mole rats are very aggressive, but will retreat if severely outmatched. They fight for their food by biting at prey with their large incisors. When attacking, mole rats charge towards their opponents and have a long melee range, with the ability to lunge several feet. They are also pack animals, which means if one is spotted, there are likely more in the surrounding area.
Mole rats are hostile unless the Lone Wanderer has Animal Friend perk, and they will help the Lone Wanderer in battle if he/she has the second rank of the Animal Friend perk.
Moira Brown noted in her computer terminal that mole rats can be domesticated, but only after de-clawing, de-teething, and a lobotomy, although Pumpkin seems to disprove this.
Pumpkin is a tamed mole rat found in the office of Ryan Brigg, a scientist experimenting with mole rats in order to enhance the taste of mole rat meat. She is located in the Jury St. tunnels. She is non-hostile towards the Lone Wanderer and is found locked in a cage. There is no known way to set her free.