Q Where do moles occur?
A Moles (Talpa europaea) are common throughout England, Scotland and Wales, but do not occur at all in Ireland. They live wherever the soil is deep enough and there is sufficient food. The perfect garden loam, well-worked and rich in earthworms, is perfect for moles too.
Caption: Molehills can be a problem in lawns
Q How do I recognise them?
A Moles are 11-16cm long, with a short tail, short, dense black fur, large pink feet and tiny eyes (though they are not blind). They are not often seen as they only rarely venture out on to the surface, and then only at night. You may sometimes find one killed by a fox, dog or cat.
Q What sort of damage is caused by moles?
A Moles live almost exclusively underground. Molehills consist of earth pushed up to create tunnels and they are often the only sign of a mole’s presence. They are also the main problem moles create. Digging can produce low ridges in shallow or very compacted soil when tunnels are near the surface. Tunnelling can also uproot growing plants or leave their roots dangling into space underground.
Q Can you tell me more about them?
A Moles tunnel most actively in late winter and early spring. They are highly territorial and lead mostly solitary lives, patrolling individual networks of tunnels. These may be up to 50m long for males, less for females. Moles are insectivores and need to eat about half their own body weight each day. Earthworms are their main food but they also eat wireworms, leatherjackets, chafer grubs and carrot-fly larvae. A lot of prey is collected by patrolling existing tunnels. New excavations occur when food is scarce, when males go looking for females and when females construct nest chambers.
Q How can I deter moles?
A Your success in persuading moles to move elsewhere will depend more on the availability of attractive alternatives sites. Sometimes the noise of regular mowing, or children playing, will discourage them. But if adjacent areas are unattractive to them they can be very tenacious. Methods for discouraging moles are usually based on strong smells, sound or vibration. In a Which? Gardening members' trial, a few people found pickled onions, or the smelly repellents (which smell of foxes), had some effect. However, strong smells are more likely to create even more disturbances, as moles tunnel around the offending substance.
Q What about noise or vibration?
A Noise and vibrations said to drive out moles include burying bottles up to their necks so the wind makes a noise blowing across them, and setting up children's windmills to create whirring noises. Again there is little likelihood of these working and they may well annoy you more than the moles! Moles rapidly acclimatise to new sounds, so even if they do move off for a while, they are likely to come back.
Q What about ultrasound deterrents?
A There is nothing special about ultrasound or 'sonic' deterrents – they simply produce a noise that humans can't hear, and are no more effective than other noises. In addition, ultrasound can’t travel through the ground so it’s particularly unlikely to affect moles. The Advertising Standards Authority has challenged manufacturers of these products to supply evidence of their effectiveness, but they have failed to do so. We do not recommend them.
Q So is there any way to get rid of moles permanently?
A The short answer is probably no, unless the mole population suffers a natural decline or they simply decide to move elsewhere. It is legal to kill moles, but this must be done as humanely as possible.
Only professional mole catchers can use poison and then not near houses. However, killing moles often achieves little, as young moles will move in from local territories.
Q What other options are there to reduce mole damage?
A Molehill soil has long been prized as good potting soil and is excellent for top-dressing the lawn, so collect it up or scatter it carefully, don’t block the tunnels.
Getting rid of earthworms has sometimes been suggested as a way to discourage moles. In fact there are no approved chemicals for disposing of earthworms and, in any case, removing them could do long-term damage to the soil’s structure. The more worms you have, the less damage the moles do as they need to make fewer tunnels to find enough food.