In 1998, researchers observed naked mole-rats using wood shavings and tuber husks as tools. The little rodents place the shaving or husk in their mouth behind their incisors, so that they can gnaw away without ingesting harmful debris. Deprive them of access to their tools, and they will refuse to gnaw through plastic or other materials that would be unpleasant to ingest.
Not only do these peculiar little rodents use tools, an accepted hallmark of cognitive ability, but their brains are simply unique among vertebrates. In 2002, another study found that their brain organization is supremely specialized for their lifestyle, with over 1/3 of their somatosensory cortex devoted to representations of their incisors. Further, the somatosensory cortex is hugely enlarged compared to close relatives, and the areas of the brain that are usually associated with vision have been repurposed to serve as part of the somatosensory cortex.
That's totally fine, because naked mole rats live in complete darkness and are equipped with an array of sensory hairs and cells on their backs and tail. They can run backwards as quickly as they can run forwards, a skill unquestionably aided by the ability to "see" backwards.
In case that's not enough, the naked mole rat lives to be 25 years old, an age far older than what would be expected from a tiny rodent (mice live to be about 3). They can survive long periods of oxygen deprivation that would kill any other mammal, and aren't affected by toxic chemicals and metals in the soil where they live and burrow. Further, these little rodents are cancer-resistant due to a gene that is unique among mammals.
In other words, naked mole-rats have a suite of traits -- subterranean lifestyle, cancer resistance, intelligence, longevity, sociality -- that will uniquely equip them to one day rule the world.
Naked mole-rats (Heterocephalus glaber, Rodentia: Bathyergidae) excavate extensive subterranean burrows with their procumbent incisors. Captive individuals often place a wood shaving or tuber husk behind their incisor teeth and in front of their lips and molar teeth while gnawing on substrates that yield fine particulate debris. This oral barrier may prevent choking or aspiration of foreign material. Consistent use of tools has rarely been reported in rodents.