Moles are small cylindrical mammals adapted to a subterranean lifestyle. They have velvety fur; tiny or invisible ears and eyes; and short, powerful limbs with large paws oriented for digging. The term is especially and most properly used for the true moles, those of the Talpidae family in the order Soricomorpha found in most parts of North America, Asia, and Europe. It also refers to other completely unrelated mammals of Australia and southern Africa which have also evolved the mole body plan; while it is not commonly used for some talpids, such as desmans and shrew-moles, which do not fit the common definition of “mole” as well.
|Moles are classified as a pest due to their tunneling habit. The most common complaints include the following:
Moles have polydactyl hands; each hand has an extra thumb (also known as a prepollex) next to the regular thumb. While the mole’s other digits have multiple joints, the prepollex has a single, sickle-shaped bone which develops later and differently than the other fingers during embryogenesis from a transformed sesamoid bone in the wrist. This supernumerary digit is species-specific as it is not present in shrews, the mole’s closest relative. Androgenic steroids are known to affect the growth and formation of bones and there is a possible connection between this species-specific trait and the “male” genital apparatus in female moles in many mole species (gonads with testicular and ovary tissues).
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.
The Star-nosed Mole can detect, catch and eat food faster than the human eye can follow (under .3 seconds).
Making Mountains out of Molehills
Moles are considered to be agricultural pests in some countries, while in others, such as Germany, they are a protected species but may be killed if a permit is received. Problems cited as caused by moles include contamination of silage with soil particles making it unpalatable to livestock, the covering of pasture with fresh soil reducing its size and yield, damage to agricultural machinery by the exposure of stones, damage to young plants through disturbance of the soil, weed invasion of pasture through exposure of fresh tilled soil, and damage to drainage systems and watercourses. Other species such as weasels and voles may use mole tunnels to gain access to enclosed areas or plant roots.
Moles burrow lawns, raising molehills and killing the lawn, for which they are sometimes considered pests. They can undermine plant roots, indirectly causing damage or death. However, contrary to popular belief, moles do not eat plant roots.
However, in many gardens, the damage caused by moles to lawns is mostly visual, and it is also possible to simply remove the earth of the molehills as they appear, leaving their permanent galleries for the moles to continue their existence underground.