House martins nesting on your house: what you can and cannot do

House martins earned their name by nesting on houses. Their cup-shaped mud nests, tucked under the eaves, are a sign of summer, and most households are pleased to have them. Occasionally a nest is in an awkward place, usually above a door or window, and the droppings become a nuisance. There is a lot you can do about that, but removing an active nest is not one of them.

01How to recognise a house martin

House martins are small birds, about 12 to 13cm long. They are glossy blue-black above and pure white below, with a white rump that is easy to see in flight, a short forked tail and white feathered legs. Swallows, which they are often mistaken for, have long tail streamers, a red throat and usually nest inside barns and outbuildings rather than on the outside walls of houses.

House martins spend the winter in Africa. They arrive in the UK from around April and leave by October, feeding on flying insects caught on the wing.

02Their nests

The nest is built from hundreds of small pellets of mud, collected from puddles and pond edges, and lined with grass and feathers. It sits tight under the eaves or a window head, with a small entrance hole at the top. Building one takes a pair a week or two of work, which is why they often come back to the same nest, or the same spot, year after year. Pairs often raise two broods, so a nest can be in use from late spring into early autumn.

House martins also like company. Where one pair nests successfully, others often join them along the same eaves.

03What problems can they cause?

• Droppings on windows, sills, walls, paths and cars below the nest. This is the most common complaint.
• Noise from chattering adults and chicks, which some people notice in a bedroom just below.
• Nests in awkward places, such as directly over a front door.

House martins do not damage the structure of a house, and they pose no meaningful risk to people.

04What the law says

All wild birds in Great Britain are protected under the Wildlife and Countryside Act 1981. It is an offence to kill or injure a house martin, to take or destroy its eggs, or to take, damage or destroy its nest while the nest is being built or is in use. House martins are red-listed as a bird of the highest conservation concern in the UK, so there is no general licence that lets a householder remove nests because they are a nuisance.

That means a nest with birds building, eggs or chicks must be left until the young have flown and the birds have finished with it. Blocking the entrance, or fitting netting or spikes that stop the adults reaching an active nest, is against the law.

05Living with house martins

• Fit a droppings board. A narrow shelf fixed on brackets on the wall below the nest catches most of the droppings. Fix it well below the nest so it does not give predators a platform, and make it easy to lift off and clean.
• Protect what is underneath. Move the car, or cover the area below the nest during the breeding season.
• Leave the nest in place over winter. If it is not causing a problem, the same birds may return to it, which saves them the work of rebuilding.

06If a nest is in the wrong place

If house martins are nesting somewhere that causes a real problem, the lawful approach is to wait. Once the birds have left for the winter and the nest is no longer in use, the area can be cleared and fitted with a deterrent, such as netting or a smooth surface they cannot build on, before they return in spring. Anything fitted must be installed so it cannot trap birds.

Because the species is declining, the best outcome is to move them, not lose them. Leaving other parts of the eaves available, or fitting artificial house martin nest cups in a more convenient spot, gives the birds somewhere else to go.