10 Signs of a Rat or Mouse Infestation in Your West Midlands Home
Rats and mice are the most common pest call-outs across the West Midlands — from Birmingham terraces to rural Staffordshire and Warwickshire homes. The trouble is, by the time you actually see one, the colony is usually well established. Rodents are nocturnal, cautious, and very good at staying out of sight.
The good news: they leave a trail. If you know what to look for, you can spot an infestation in days rather than months — which is the difference between a quick visit and a multi-week treatment plan.
1. Droppings — the single clearest sign
Fresh rodent droppings are dark, moist and shiny; old ones go grey, dry and crumble when prodded. You'll typically find them clustered along walls, inside cupboards under the sink, behind the cooker, in the loft, or anywhere food is stored.
Rat droppings are roughly the size of a grain of rice (10–20 mm) with blunt ends. Mouse droppings are smaller, around 3–8 mm, and pointed at one or both ends. Finding a lot in one spot suggests a feeding or nesting area nearby.
2. Gnaw marks on wood, plastic and cables
Rodent teeth never stop growing, so they chew constantly to keep them in check. Look for fresh, light-coloured gnawing on skirting boards, door frames, food packaging, plastic pipes, and — most dangerously — electrical cables. Old gnaw marks darken with time and dust.
Chewed cables are a leading hidden cause of house fires, which is why a confirmed rodent presence shouldn't be left for long.
3. Scratching, scurrying or thumping at night
If you can hear movement in the walls, ceilings or under the floorboards — usually between dusk and the early hours — it's almost always rodents or, less commonly, squirrels. Mice tend to make a light, fast scratching sound; rats are heavier and you'll often hear distinct thumps as they jump down from joists.
4. A musky, ammonia-like smell
An established infestation produces a distinctive sour, musky odour from urine and oils on their fur. It's often strongest in cupboards, lofts and behind kitchen units. A sudden bad smell that you can't trace to bins or drains is a strong indicator.
5. Greasy 'runs' along walls and skirting
Rodents follow the same routes nightly and have oily fur that leaves dark smudge marks (smear marks) along the walls they brush against. Check the lower few centimetres of skirting boards, the edges of pipes coming through walls, and beam edges in lofts.
6. Nests made from shredded material
Rodents shred soft materials — loft insulation, cardboard, fabric, paper — into ball-shaped nests, usually in warm, hidden spots: airing cupboards, under floorboards, behind the boiler, inside the oven panel, or in storage boxes you haven't opened in a while.
7. Footprints and tail-drag marks in dust
In dusty areas like lofts, garages and behind appliances, you may see small footprints and a thin line where the tail has dragged. Sprinkling a thin layer of plain flour overnight in a suspect area is a cheap, harmless way to confirm activity.
8. Disturbed food and chewed packaging
Bags of pasta, rice, cereal, dog food, bird seed — anything in soft packaging is fair game. Look for small holes chewed in corners, spilled grains in the cupboard, and gnaw marks on plastic tubs. Rodents will also drink from pet bowls and toilet bowls if they're easy to reach.
9. Pets behaving strangely
Cats and dogs can hear and smell rodents long before you can. Persistent staring at a wall, scratching at skirtings, or sudden interest in the back of a cupboard or under the sofa is worth investigating.
10. An actual sighting
Spotting a rodent during the day usually means the population has outgrown its hiding space and is being forced out to find food. By that point you're not looking at one or two animals — you're almost certainly dealing with a breeding colony.
Rats vs mice — quick identification
Knowing which species you have changes the treatment plan, baiting strategy and the price.
- Mice: small (6–9 cm body), grey-brown, very curious, will explore new objects. Droppings 3–8 mm, pointed.
- Brown rats: large (20–25 cm body, plus tail), heavier build, far more cautious of new objects (this is why DIY snap traps often fail). Droppings 10–20 mm, blunt.
- Mice can squeeze through gaps the size of a biro; rats need a hole roughly the size of a 2p coin.
What to do right now
If you've ticked two or more of the signs above, treat it as an active infestation rather than a one-off visitor. The sooner you act, the smaller (and cheaper) the job.
- Move all open food into sealed glass or hard plastic containers.
- Empty kitchen bins nightly and check pet food isn't left out.
- Walk the outside of the property looking for gaps around pipes, vents, airbricks, and under doors — block anything wider than a pencil.
- Avoid laying shop-bought poison if you have pets, children, or live near wildlife — secondary poisoning is a real risk and a professional uses tamper-proof bait stations.
- Get a survey from a licensed West Midlands pest controller. Most will tell you over the phone whether you need a callout or just some sealing work.
When to call a professional immediately
Some situations don't suit a wait-and-see approach: rodents inside a food business, a sighting in a bedroom or child's room, signs of chewed electrical cabling, a smell that suggests a dead animal in the walls, or any infestation in a rented property where a landlord obligation is involved.
A professional will identify the species, find the entry points, treat with the right method (often a mix of trapping and proofing — not just bait), and document everything for your records.
Frequently asked questions
How quickly can rats or mice spread in a house?
A single pair of mice can produce 30–60 offspring per year, with new mice able to breed at 6 weeks old. Rats are slower but a colony can easily double in a season. Acting in the first 1–2 weeks dramatically reduces the work needed.
Do I have rats or mice if I only hear scratching at night?
Both are nocturnal, so the time of day doesn't tell you much. Light, fast skittering usually means mice; heavier thumps, especially from above, point to rats or squirrels. A 10-minute survey can confirm it.
Will the smell go away after treatment?
Yes — once the source is removed and the area is cleaned and disinfected. A pro will identify any deceased animals trapped in cavities, which is the usual cause of lingering odours.