Basic mole facts about the European Mole, or Talpa Europaea

Recognition: 

Moles are short mammals with (usually) black fur. They have spade-like forelimbs and a pink fleshy snout. Head/body length: 113-159mm. Tail: 25-40mm. Weight: 72-128g. Males are usually larger. 

General Ecology:

Moles are found throughout Britain but not in Ireland. An ice age wiped them out in Ireland, and it was then cut off by sea before they could re-colonise.  

They are present in most habitats where the soil is deep enough to allow tunnelling but are uncommon in coniferous forests, on moorlands and in sand dunes – probably because their prey is scarce. 

Behaviour

Moles spend almost all their lives underground in a system of permanent and semi-permanent tunnels. Surface tunnels are usually short-lived and occur in newly cultivated fields, in areas of light  soil and in very shallow soils, where prey is concentrated just below the surface. A system of permanent deep burrows is more usual and these form a complex network hundreds of metres long  and at varying depths in the soil. The deeper tunnels are used most in times of drought and low temperatures. Permanent tunnels are used repeatedly for feeding over long periods of time, sometimes by several generations of moles. 

Within the tunnel system moles construct one or more spherical nest chambers, each lined with a ball of dry plant material.  The nests are used for sleeping as well as raising their young. 

Diet

Earthworms are the most important component of the mole’s diet; an 80g mole needs 50g of earthworms per day. Moles also eat many insect larvae, particularly in the summer. Earthworms dominate the winter diet. Moles sometimes collect and store them alive in special chambers. The stored worms are immobilised by a bite to the head segment, and 470 worms have been recorded in one chamber. Food is either actively dug out of the soil by the mole or more often collected from the floor of the tunnel. Many soil animals fall through into the tunnels. Moles rarely forage on the surface, and then most often in times of drought. 

Reproduction

Males and females are solitary for most of the year, and occupy exclusive territories. With the start of the breeding season males enlarge their territories, tunnelling over large areas in search of females. A litter of 3 or 4 naked babies is born in the spring. They start to grow fur at 14 days, eyes open at 22 days and they are weaned at 4-5 weeks. The young start to leave the nest at about 33 days and disperse from their mother’s range at 5-6 weeks. Dispersal takes place above ground and is a time of great danger. Moles are sexually mature in the spring following birth. 

Most moles don’t live beyond 3 years but can live up to 6 years. Their main predators are owls, buzzards, stoats, cats and dogs but vehicles and humans also kill many. 

Conservation

Moles have no legal protection in the U.K. and are frequently regarded as pests by farmers, horticulturists and green-keepers. Surface tunnelling in newly planted fields may disturb plant roots so much that they will wilt and die. Mole hills cause damage to farm machinery, and can also cause contamination of grass used to make silage. 

A hundred years ago moles were trapped in large numbers for their pelts but today they are killed as pests. 

Moles can be beneficial to man, preying on many harmful insect larvae such as cockchafers and carrot fly, while their tunnels help drain and aerate heavy soils. 

Scientists estimate the UK mole population to be in excess of 30 million.

Frequent Questions

How do moles dig?

Moles use their fore limbs to dig,  shearing soil from the sides of the tunnel with alternate strokes. They use their hind limbs to brace their body against the tunnel walls. The mole turns round, scoops up accumulated soil with its fore limbs and pushes it along a previously dug side tunnel leading to the surface. The soil is pushed out above ground to form a molehill. 

What is a mole fortress?

Moles sometimes construct very large mounds containing more than 750kg of soil. The mounds have an internal structure with one or more nests and a network of tunnels; they can also have food stores. Both males and females will build them, and they occur most often in areas with shallow soil on hard substrate and in areas prone to flooding. The fortress acts as a refuge in times of flooding and also helps insulate the nest against low temperatures. 

See also the Wikipedia entry