What bird is it?
There are very few birds that will nest in the roof space or under your eaves. Since most of the birds are fully protected by law, their identification is vital if correct action is to be taken.
House sparrows and starlings are the most likely species to share your home. They normally enter the roof-space through a gap between the roof tiles and the gutter.
House sparrow: a small, brown bird, 14.5 cm (6 inches) long, which cheeps a lot. Male is streaky red-brown on back, grey on top of head with black chin. Female is paler brown, streaked on top, unmarked below.
Starling: 21 cm (8 inches) long. Adult is blackish, glossed green and purple, with pointed yellow bill. Juvenile is dull brown with black bill and mask. Makes noisy whistles, rattles and crackles. Can be heard walking around inside roof.
Feral pigeon: 32 cm (13 inches) long. The familiar town square pigeon which is really a domestic pigeon gone wild. Anything from black to white, grey or brown. If roof damage has created large holes, they may move in.
On the outside of the building, high up under the eaves, house martins may build their mud nests. They will not, however, enter your roof space. House martins are 15 cm (6 inches) long, blue-black with white underside and square white patch on back at the base of the tail. Fully protected at all times. Do not interfere with the nest:; if it has collapsed, contact the RSPB for guidance. A shelf fitted below the nest will catch droppings.
Swifts seek dry, safe sites just inside the roof, usually entering where overhanging roofing felt is torn or where soffit boarding has become rotten. Swifts are 25 cm (10 inches) long, sooty brown, with very long, sickle-shaped wings and a forked tail. Their legs are very short, and hence they are practically immobile once they land, so they will not walk around inside your roof. Fully protected at all times. Do not interfere with the nest.
Jackdaws and swallows may nest in old cottages with very wide chimneys, but modern homes do not have enough chimney space.
In the country, owls sometimes make use of roofs. Barn owls will live up to their name in an area with plenty of mice and voles, but they are unlikely to enter an occupied home. A broken roof tile will let in little owls and, exceptionally, tawny owls. Fully protected at all times and nests must not be interfered with. Barn owls must not even be disturbed when at or near their nest. Occasionally, blue tits and great tits will use holes in house walls, where an old pipe has been removed or brick has crumbled.
Some birds will use drain pipes and may die if they explore deep, narrow pipes and cannot get back out. Sparrows will also use downpipes or bathroom ventilation pipes, and a broken ventilation grille will provide nest sites for sparrows and starlings.