Pest Control
Rats in your loft? Here's what you need to know
Heavy scratching overhead at night, large droppings and greasy marks on the joists. The signs of rats in the loft, how they get in and what to do.
Heavy scratching and scurrying above your head at night is unsettling, and in a loft it often means rats. A rat that has found a way into a roof space is usually nesting there, not passing through. Here is how to recognise the signs, how they get in and what to do.
The short version
- Rats in a loft are almost always brown rats, which climb well and get in through gaps at roof level and inside cavity walls.
- Look for heavy movement at night, droppings 12 to 20mm long, gnawed timber or cables, and greasy marks along their routes.
- Deal with the rats before sealing the way in, or you risk trapping them inside the house.
Why lofts are rat heaven
Lofts are warm, dry, dark and rarely disturbed. The brown rat, Rattus norvegicus, is the species in almost every British loft. It is a better climber than people expect, and gets up to the roof inside cavity walls, up ivy and climbing plants, along cables and up the outside of drainpipes.
Once settled they breed quickly. A female brown rat can have several litters a year, commonly of six to ten young, and the young are breeding themselves within a few months. A couple of rats in autumn can become a much bigger problem by spring.
Tell-tale signs of rats in the loft
- Noise at night. Heavier, slower movement than mice, with scratching, gnawing and sometimes squeaking, mostly after dark.
- Droppings. Dark brown, capsule-shaped with blunt ends, about 12 to 20mm long. A cluster in one spot means they are using it regularly.
- Gnawing. Rats gnaw constantly to keep their teeth worn down. Look for chewed timber, pipework, boxes and electrical cables.
- Disturbed insulation. Tunnels, flattened runs and shredded material pulled together into nests.
- Smear marks. Dark, greasy marks along joists, beams and around holes where their fur rubs on the same route night after night.
- Smell. A strong, stale ammonia smell from urine. A sweet, rotten smell may mean a rat has died somewhere in the roof space.
Lighter, quicker movement and small droppings point to mice instead. Our guide on telling rats from mice in a loft explains the differences.
Why you can't ignore a rat problem
- Health. Rat urine and droppings can carry diseases including leptospirosis, and contaminate insulation, stored belongings and surfaces.
- Fire risk. Gnawed cables can short and overheat. It is one of the main reasons rats in a roof space need dealing with promptly.
- Damage. Chewed timbers and pipes, fouled insulation and ruined belongings can be expensive to put right.
- Sleep. Night after night of noise above a bedroom wears people down quickly.
How they get in
An adult rat can squeeze through a gap of around 15 to 20mm. Common routes into a loft include:
- gaps around pipes, cables and vents at roof level, and under roof tiles
- damaged air bricks, soffits and fascias
- uncapped or poorly capped chimneys
- the inside of cavity walls, often from a defective drain or an old pipe entry at ground level
- overhanging branches, ivy and climbing plants that reach the roof
When rats are in a loft with no obvious gap at roof level, the route is often from below. A drain survey can find a broken or redundant pipe that lets rats into a wall cavity.
What to do if you suspect rats
- Do not wait. Rats do not leave on their own once they have found a warm nest site.
- Remove food sources around the house: spilled bird food, open bins, pet food left out and compost heaps with food waste.
- Cut back branches, ivy and climbers that touch the roof or walls.
- Leave droppings alone until you can clear them safely: gloves on, dampen with disinfectant first, never sweep or vacuum dry.
- Do not seal holes yet. Blocking the way in while rats are still inside can trap them in the house and push them into living areas. Clear them first, then proof.
When to call us
Rats in a loft are a job for a professional. We confirm what you have, find where they are getting in, deal with the rats and then proof the building, in that order. Our rat control page explains the process.
More pest guides
Mice in the loft? How to spot them, and stop them
Light scratching overhead after dark, small droppings by the insulation. How to confirm it is mice, how they are getting in, and how to stop it for good.
Read the guide →The British mice identification guide
Britain has several kinds of mouse, but only a couple cause trouble indoors. How to tell a house mouse from a wood mouse, and why it changes what you do next.
Read the guide →Not sure what you're looking at?
Send us a photo or describe it. We will tell you what it is, whether it needs treating at all, and what it would cost, before anyone comes out.