Moles

Advice leaflet about Moles

The mole is a member of the Insectivore Order and is abundant throughout mainland Britain. It is found wherever there are suitable soils for tunnelling, but it tends to avoid shallow or stony soil, waterlogged or very acidic soil. It is most abundant in permanent grassland and deciduous woodland but can be found in playing fields, parks, golf courses and private gardens.

Key Features

The cylindrical body is 12-16cm long from nose to tip of tail and weighs 70-110gms. There is very little external difference between the sexes. The mole is covered with black velvety hair which can set in any direction. It is well adapted for burrowing with large spade-like forefeet turned permanently outwards for digging. The eyes are very small and hidden among the fur, but well capable of detecting light. There are no external ear flaps. The senses of touch and hearing are well developed but smell and sight are less important.

Breeding

The breeding season lasts from February to June. The gestation period is 4 weeks after which the young are born blind and without fur. The mother feeds them for 4-5 weeks and after this period the young leave the nest and start to catch food for themselves.

Shortly after this they will leave the nest site and search for a new home of their own. During this dispersal period, as they tend to move above ground, they are more vulnerable and fall victim to predatory birds' etc.

Signs of Presence

The most obvious sign of the presence of moles is the appearance of mole hills on the surface of the ground. These consist of heaps of loose soil, usually sufficient in volume to fill a 5-litre bucket. The main way to check whether moles are still present in an area is to level the hills, e.g. by harrowing, and check after 2 to 3 days for formation of new hills. This indicates the area where control action should be concentrated.

There are 2 types of tunnel: deep tunnels 5-20cm below the soil surface, the soil from which is pushed out onto the surface as mole hills; and surface runs where the soil is pushed up to form a ridge on the surface of the ground. Nests for breeding and sleeping are made of dry grass and leaves either in part of a deep tunnel or in the centre of a large mound of soil known as a fortress.

By opening up deep tunnels it is possible to see whether they are in active use. Smooth sides and claw marks indicate that moles are present, whereas rootlets growing into the tunnel and signs of partial collapse indicate that the tunnels are disused.

Prevention of Damage and Control

Because moles feed on earthworms, killing the worms in an area of turf will make it unattractive to moles. However, the turf will require additional maintenance, e.g. aeration by spiking to replace the beneficial effects of earthworms and keep it in a healthy condition. This method is only practicable on high value, amenity grassland such as golf and bowling greens where, in any case earthworms are unacceptable because of their casts. Only products approved specifically for use as a lumbricide (earthworm killer) may be used for this purpose.

Various repellent devices are marketed from time to time which are said to repel moles e.g. by interfering with the Earth's magnetic field. In general little confidence can be placed in their efficiency. Similarly, there are a number of traditional remedies varying from burying milk bottles up to their necks (the vibration of wind blowing across the mouth of the bottle is said to repel moles) to lying prickly vegetation in mole runs. All these traditional methods are of equally doubtful effectiveness.

The only effective way to control moles, without using poisons, is to trap them. Mole trapping is a skilled job, best done by an expert. Moles are clever creatures, however, and can learn to avoid traps. Trapping is not a long-term solution and will have to be repeated every year or so.

The use of approved poisons

Only approved poisons may be used. A DEFRA permit and the appropriate training is required by persons treating moles by this method.

Local Authority Service

The council has adopted a neutral policy on moles and as such the Public Health Department does not offer a control service for moles.

Some private pest control contractors listed in the Local directory will carry out treatments; we are unable to comment on the effectiveness, cost or availability of any company or individual.