Beech marten

( Latin: Martesfoina)

In many parts of Europe (although not Britain) beech martens occur quite commonly on farms and in holiday houses in the country. They sometimes live in the lofts where they make their lairs in hay or straw, or even in the roof insulation. The 2-5 young are born in late April. The adults catch rats and mice, and also take quite a number of birds and their eggs.

Normally martens are not much seen, for they start to hunt about an hour or two after midnight, having first moved around the loft for an hour or so. They return home at 5-6 o’clock in the morning and go to sleep again, after another stroll. Apart from this habit of wandering around at night martens normally cause no great trouble. Sometimes, however, their drop- pings and the remains of their prey are a nuisance, and they also damage insulating • materials when making their lair (see also under ‘thatch’, p. 161).

If martens do become a nuisance they can be driven away by laying down strong- smelling substances in the loft, such as naphthalene or ammonia. They are also sensitive to noise and will usually move off if continually disturbed over a period. Once they have been driven away their means of access must be blocked, otherwise new ones will quickly move in.

Beech martens are very skilful climbers, and they can get through gaps with a diameter of only 6 cm. They often find their way up to the roof by using espalier fruit trees, drainpipes or even large trees growing close to the house. Their route can sometimes be traced by the tracks or footprints they leave (p. 210).


( Latin: Order Chiroptera)

Bats, which are the only true flying mammals, are active by night, spending the day, and the winter, in sheltered places. Most of them probably live in hollow trees and caves, but some make use of buildings, where they are found mainly in lofts.

There are about a dozen different bat species in northern Europe, and of these the serotine (Ep’tesicus serotinus) and the pipistrelle (Pipistrellus pipistrellus) are perhaps the species most commonly found in buildings.

Despite a certain amount of human distrust and aversion, bats are completely harmless lodgers that neither gnaw nor in any other way damage the building.

In northern Europe bats feed on insects, which they can catch in the air. When in flight, they emit continual ultra-sonic sounds, which are reflected back to their ears by insects and other objects in the vicinity.

Bats will bite if one tries to catch them.

They normally live in colonies, and if there are fifty or so in a loft they naturally produce rustling and piping sounds. It has been noticed that there is always a certain amount of unrest in a colony in the early evening, just before the bats fly out to hunt.

Their droppings, which accumulate below their resting places, are somewhat similar to those of mice, but can easily be distinguished on closer examination (p. 209).

Bats can be driven away from a building if they are subjected to constant disturbance, or to strong-smelling substances such as naphthalene. However, they often return and the only effective way of. keeping them out of a building is to block all means of access.


( Latin: Family Strigidae)

Among the owls that breed from time to time in buildings perhaps the best known is the barn owl (Tyto alba) which frequently nests in farm buildings or on church towers. In some areas the little owl (Athene noctua) will also nest m buildings, mainly in farming country.


( Latin: Falco tinnunculus)

This bird of prey often builds on church towers in the country, and is by no means uncommon as a breeding bird in towns and cities, particularly in southern Europe. On occasion they also use the deserted nests of crows or magpies. They feed mainly on mice, but also take quite a few large insects, such as beetles.


( Latin: Corvus monedula)

In places without human habitation, jackdaws will build in hollow trees, but in towns and villages they find good nest sites on houses, and particularly in chimneys.

Rock dove

( Latin: Columba livia )

Wild rock doves build mainly on cliffs, often at a considerable height. The ordinary urban pigeons which nest on buildings in towns and cities belong to this species. They require very little nest material, and sometimes a nest consists only of a cake of droppings with a few straws or twigs. They start egg laying quite early in the spring and may produce 2-3 broods during the season.

Domestic pigeons may cause considerable damage by fouling the buildings they nest on, and their nests provide shelter for irritating invertebrates which may then invade flats and annoy the occupants. They are also thought to be involved in the spread of certain diseases.

Various methods of controlling these ubiquitous birds have been devised, but most only work for a short time. The only efficient measure is to deny them nest sites by barring access to cornices, closing roof lights and so on.

House sparrow

( Latin:  Passer domesticus)

These familiar little birds are probably more dependent upon man than any other. They live in small colonies, and build their nests close together.

House sparrows are stationary birds, and after they have started to breed in a place they will remain there for the remainder of their life which may be 3-4 years. They use the nests to sleep in during the winter.

In March and April the breeding birds collect nest material, mainly dry grass, hair, feathers and scraps of paper, which they use to build their untidy more or less spherical nests. A pair may rear two or three broods in the course of the summer. House sparrows forage on the ground, often in flocks. The young are fed on insects, but the adults live mainly on seeds and in towns on household waste. In the country they frequently invade stores of grain and fodder. They cause serious damage to stored foodstuffs


( Latin: Apus apus)

Swifts originally nested in hilly country, but they are now much associated with buildings, such as churches, silos and factories, where they build high• up in sheltered, inaccessible places.

They arrive in Britain in late April and May and start to collect nest material. This takes place in the air, where they snap up scraps of dry grass, paper, feathers and anything else that is blowing around.

A pair remains together year after year, often using the same nest, which gradually accumulates a mass of material. Perhaps no other European bird spends quite so much time in the air, where it feeds exclusively, of course, on insects taken on the wing.


Several birds have come to depend upon buildings when looking for a suitable nesting site. These are birds which have originally built on cliffs or in hollow trees, and each species chooses a position on the building which corresponds with its original nesting habits.

In most cases birds are regarded as welcome guests, and many give great pleasure. It should, however, be remembered that birds’ nests may be the source of certain parasites and of some pests of textiles (see pp. 36, 41, 43, 45, 49 and 94).

This familiar bird is very dependent upon buildings. It may nest inside a building, for instance, under the roof of a stable where there is continuous access to the outside, or it may build under the eaves.

The nest is in the form of a hemispherical saucer of mud mixed with earth and a little straw. Swallows are territorial, so there is usually a fair distance between the individual nests. They often return to the same nest year after year, and in Britain they usually start to lay eggs in the middle of May.

They feed on insects, mainly flies, gnats, midges, which are caught in the air.

In the wild house martins build on cliffs but many make use of buildings. They always nest on the outside of buildings, often in small colonies, but occasionally there may be hundreds together. They build high up, rarely less than 3 m from the ground, and the nest which is constructed of mud is completely enclosed with a small entrance hole at the top.

Bathroom fly

( Latin: Psychoda alternata )

These are small, dark flies which can some- times be seen on the walls and in the basins in bathrooms and lavatories. They belong to a group known generally as owl midges.

Their wings are hairy and relatively large, but they do not fly particularly well. They move by a kind of hopping flight, or simply walk around.

The eggs are laid in the slime that accumulates in water-traps and outlets of basins. The larvae live in this coating of slime, which is continually damp but not covered with water the whole time, and they feed on any organic matter present and on bacteria, algae and fungi.

These little flies are naturally rather annoying to have around but they do not sting nor do they cause any damage. In the filters of purification plants they can be regarded as beneficial, because there the larvae help to break down organic waste. In the house they are best controlled by removing the slimy deposit that the larvae live in. This can be done by pouring boiling water into the outlets and water traps. A watch should also be kept on the overflows of basins as these provide excellent living conditions for the larvae.