A mole’s diet primarily consists of earthworms and other small invertebrates found in the soil and also a variety of nuts. Because their saliva contains a toxin that can paralyze earthworms, moles are able to store their still living prey for later consumption. They construct special underground “larders” for just this purpose; researchers have discovered such larders with over a thousand earthworms in them. Before eating earthworms, moles pull them between their squeezed paws to force the collected earth and dirt out of the worm’s gut.
Although the mole can be eaten, the taste is said to be deeply unpleasant.
The eyes of moles and of some burrowing rodents are rudimentary in size, and in some cases are quite covered by skin and fur. This state of the eyes is probably due to gradual reduction from disuse, but aided perhaps by natural selection. In South America, a burrowing rodent, the tuco-tuco, or Ctenomys, is even more subterranean in its habits than the mole; and I was assured by a Spaniard, who had often caught them, that they were frequently blind. One which I kept alive was certainly in this condition, the cause, as appeared on dissection, having been inflammation of the nictitating membrane. As frequent inflammation of the eyes must be injurious to any animal, and as eyes are certainly not necessary to animals having subterranean habits, a reduction in their size, with the adhesion of the eyelids and growth of fur over them, might in such case be an advantage; and if so, natural selection would aid the effects of disuse. (Charles Darwin, The Origin of Species, Laws of Variation)
Since the modern synthesis, Darwin’s suggestion that the mole’s eye became small “probably due to gradual reduction from disuse…” is no longer fully accepted by modern biologists. The Lamarckian mechanism by which increased or decreased use of an organ could influence its reproduction, which was accepted by Darwin, has been replaced by an appreciation that natural selection and random genetic variation (genetic drift) are the primary drivers.