What should I do about noises in the loft or walls?

Identifying what you have from the sound and the evidence, and the exclusion that solves it permanently.

Difficulty: intermediate
Time: 1 hr 30 min
Read: 2 min
Safety: warning

Short answer

Identify what it is from the time of day and the evidence before doing anything. Then find and seal the entry point — trapping or removal without exclusion means new animals move in within weeks.

Something living in a loft or cavity is common and usually solvable. The critical part is exclusion: removing the animals without sealing the entry point simply creates a vacancy that another takes.

Safety

Never walk on loft insulation between joists — you will come through the ceiling. Use boards and a torch. Some pests, including rats and birds, carry disease, and bat and some bird species are legally protected in many countries and must not be disturbed. Chewed wiring is a fire risk and needs professional inspection.

What you'll need

Torch
Boards to walk on
Wire wool and sealant (optional)
Gloves and mask (optional)

Step by step

Note when you hear it and what it sounds like.Scratching at night usually means rodents. Daytime activity and flapping suggests birds. Heavy movement suggests something larger. This narrows it immediately.
Inspect safely with a torch, standing on boards.Never on the insulation or the plasterboard between joists. Look for droppings, nesting material, chewed insulation and greasy marks along runs.
Identify the species before acting.Bats and many bird species are legally protected and must not be disturbed. If you suspect either, get advice before doing anything.
Find the entry point.Gaps at the eaves, missing tiles, damaged soffits, gaps around pipework. Look from outside as well as inside, and look for worn or greasy patches.
Seal the entry point after the animals have gone, not before.Sealing an occupied space traps animals inside, which is inhumane and results in a serious smell problem. Exclusion first, then seal.
Use materials they cannot chew through.Wire wool packed into gaps and sealed, metal mesh, or proper repairs. Expanding foam alone is chewed through readily by rodents.
Check wiring if you have had rodents.Chewed cable insulation is a genuine fire risk. Have it inspected by an electrician rather than assuming it is fine.
Get professional help for anything persistent or large.Rats, squirrels, wasp nests and anything protected. Professionals have the equipment, and for protected species there are legal requirements.

Tips

Remove the food source. Bird feeders, open compost, accessible bins and pet food outside all attract rodents to the building.
Cut back branches touching or overhanging the roof. They are the main route squirrels and rats use to reach a loft.
Clean up droppings and nesting material with gloves and a mask, and dispose of them carefully. Some rodent droppings carry disease.

Common mistakes

Sealing the entry point while animals are inside — It traps them, which is inhumane and produces a serious smell problem as well as further damage as they try to escape.
Removing animals without sealing the entry — The space is still accessible and attractive. New animals move in within weeks and the problem repeats indefinitely.
Walking on loft insulation — There is nothing beneath it but plasterboard. Falling through a ceiling is a common and serious loft injury.

Questions people ask

What is making scratching noises in my loft at night?

Most commonly rodents — mice, rats or squirrels. Daytime activity with flapping suggests birds. Look for droppings, chewed insulation and worn greasy marks along their routes.

How do I stop animals getting into my loft?

Find and seal the entry point once they have gone, using wire wool and sealant or metal mesh rather than foam alone, and cut back any branches touching the roof.