Mole rat Mole rats are giant rodents that were engineered by the United States before the Great War . Despite the fact that they have the same name , two species can be distinguished . The mole rats found in New California are mostly covered with fur and come from moles , and those from the East Coast and the Mojave Wasteland are furless and come from naked mole rats which come mostly from governmental experiments rather than the area , as mole rats are not native to the United States . Background . < section begin = Background / > Mole rats have sharp claws and even sharper tusks that they use to tear great chunks of flesh from their prey . Mole rats are either huge rats or the result of gene - splicing Kodiak bears with maladjusted lab rats . Fortunately , they seldom run in packs larger than a half dozen or so . < section end = Background / > Origins . According to the Pentagon Library terminal in the Citadel , mole rats in the Capital Wasteland are the result of an American government program , codenamed Mission Cloacina , to develop an invasive lifeform that could be planted in China , where its aggression and fast breeding would help undermine the Chinese war effort . It is noted that a genetic " kill switch " was included to help the US Army clean up the rats after the theoretical fall of China . Additionally , it is revealed that the researchers attempted to use the Forced Evolutionary Virus to further augment their creations , but dismissed this course of action as FEV had a tendency to render subjects sterile ( defeating the whole purpose of the rats ' being invasive ) . Biology . An Enclave field report in " Fallout 3 " classifies naked mole rats as follows : According to the report , naked mole rats most closely resemble a , also known as the sand puppy or desert mole rats . Their enlargement is due to heavy radiation exposure . While larger than their ancestors , the naked mole rats have similarly low brain function , possibly due to an exceedingly tiny brain organ . Their incisors show increased enamel and dentin growth , making them razor sharp . In addition , the naked mole rats have extremely low levels of Substance P which results in an incredible pain tolerance . Variants . Hairy mole rat . A mutated mole only found in New California . They can often be found in packs together with pig rat s and giant rat s . Hairy albino mole rat . A rare variety of intelligent hairy albino mole rat only found in New California . Their origins are unknown but like albino deathclaw , appears to be caused due to a different mutation with the FEV . They ' re a bit bigger than a normal hairy mole rat , have a light brown hair and red eyes . They can talk and have a relatively higher intelligence than the average . The only two known specimens are Keeng Ra ' at and Brain . Pig rat . In between the small giant rat and the mole rat . Mole rat . A mutated naked mole rat found in East Coast and the Mojave Wasteland . They have very little hair on their body and are usually found in packs of roughly 3 or 4 , but rarely in 2 or by themselves . Mole rat pup . These are young naked mole rats and are smaller and weaker in combat . They usually stay close to their mother . Giant mole rat . These are giant mutations of the regular mole rats in " Fallout 3 " , used as transport . They were cut from the game . Giant naked mole rat . Mean , standing over three feet at the shoulder and weighing in at around at 200 pounds , these critters are fierce and dangerous . Glowing mole rat . A particular mole rat species which has been exposed to enormous quantities of radiation . The glowing mole rat produces radiation in a short perimeter around and benefits from radiation to heal or getting his defenses reinforced . One can be found in the mole rat den . Mole rat brood mother . A powerful type of mole rat that can be encountered at high levels . The mole rat brood mother is significantly more resistant than her children , but her attacks still only do minor damage to a well - armored player character . Vault 81 lab mole rat . Found within the Vault 81 testing area , those lab mole rats will transmit the mole rat disease when hitting the player character . There are several variations of Vault 81 mole rats , ranging from the standard variant to glowing variants . Appearances . Mole rats appear in " Fallout " , " Fallout 2 " , " Fallout 3 " , " " , " Fallout Shelter " , and " Fallout 4 " . They were going to appear in the canceled " " .