Moles are small mammals mentioned briefly in the How to Train Your Dragon Book series.
Moles are mammals that live for the most part, underground. True moles belong to the Family Talpidae, though there are other creatures in other taxa that look similarly. Mole burrow underground with strong forelimbs designed for digging. They have an extremely good sense of smell, but poor eyesight. They are also able to make use of the available oxygen underground more efficiently, and can survive in low oxygen conditions.
Terms for males and females seem to be the same as those of pigs: males are 'boars' and females are 'sows'. A group of moles is called a 'labor'.
Moles primarily consume invertebrates and some plant material, with worms being a large part of their diet. In fact, moles produce a toxin paralytic to worms. This allows the moles to store the worms live for later consumption.
In the Book series, moles are mentioned as a metaphor to describe something else.
In reality, moles were once used extensively as a fur animal, as their dark fur is very soft and supple. Moles can also be a significant agricultural and garden pest.
While escaping the Hysteric Tribe Great Hall after infiltrating it during the night, Hiccup and Camicazi "appeared, blinking like moles, into the daylight". The Great Hall was dark, starkly contrasted to the dawn light outside.