mole

Small burrowing mammal with typically dark, velvety fur. Moles grow up to 18 cm/7 in long, and have acute senses of hearing, smell, and touch, but poor eyesight. They have short, muscular forelimbs and shovel-like, clawed front feet for burrowing in search of insects, grubs, and worms. Their fur lies without direction so that they can move forwards or backwards in their tunnels without discomfort. Moles are greedy eaters; they cannot live more than a few hours without food. (Family Talpidae, order Insectivora.)

North American moles differ from those of the Old World in having tusklike front upper incisor teeth. The same ecological role is taken in Africa by the golden moles (family Chrysochloridae), and in Australia by marsupial moles (genus Notoryctes, order Marsupialia).

Some members of the Talpidae family are aquatic, such as the Russian desman (Desmana moschata) and the North American star-nosed mole (Condylura cristata).

The eastern American shrew mole (Scalopus aquaticus), about 15 cm/6 in long, has blackish to coppery coloured soft, dense fur and a long snout. Its eyes and ears are not visible externally. It excavates tunnels just under the surface, leaving raised ridges, in search of earthworms and insect larvae.

mole

Unit of the amount of a substance. One mole of a substance is the mass that contains the same number of particles (atoms, molecules, ions, or electrons) as there are atoms in 12 grams of the isotope carbon-12.

One mole of a substance is 6.022045 × 10²³ atoms, which is Avogadro's number. It is obtained by weighing out the relative atomic mass (RAM) or relative molecular mass (RMM) in grams (so one mole of carbon weighs 12 g).

mole

Person working subversively within an organization. The term has come to be used broadly for someone who gives out (‘leaks’) secret information in the public interest; it originally meant a person who spends several years working for a government department or a company with the intention of passing secrets to an enemy or a rival.

The term was popularized in the novels of John Le Carré. In the UK it has been applied, for example, to the civil servants Sarah Tisdall, who leaked government information to the press, and Clive Ponting, who passed it in confidence to his member of Parliament; his successful defence was that this was legal and his duty. In Germany, the unmasking of Günter Guillaume as an East German spy working as an aide in the West German chancellery in 1974 forced the resignation of Willy Brandt as chancellor.

mole

Pigmented area on the skin. See naevus.

mole

In construction, a mechanical device for boring horizontal holes underground without the need for digging trenches. It is used for laying pipes and cables.