If you're hearing footsteps in the loft at 2am that aren't the cat, you've probably got rats. Loft rats are a year-round Cornwall problem — old buildings, generous soffit gaps, slipping ridge tiles and the warm dry insulated voids built into modern homes all add up to perfect rat habitat. This guide walks through how to confirm what you've got, what professional removal costs, what the proofing options look like, and where DIY trapping in a loft is genuinely a poor use of your time.
Rats vs mice vs squirrels in the loft
The three commonest Cornwall loft visitors sound different and leave different evidence:
- Rats — heavier footfall, occasional heavy thumps, scuttling rather than scampering. Active mostly at dusk and through the night. Droppings 10-20mm long, capsule-shaped, dark. Gnaw damage on timber and plastic; will chew through plasterboard, soft mortar, even soft lead flashings if motivated.
- Mice — lighter, faster, pattering rather than thumping. Activity throughout the night and early morning. Droppings 3-5mm, pellet-shaped. Less destructive — they nibble where rats gnaw.
- Squirrels (grey) — louder, more daylight activity (early morning and dusk), often a distinct "rolling nuts around" sound. Larger droppings (15-20mm, more sausage-shaped). See our squirrels in the loft guide for the very different legal and treatment approach grey squirrels need.
Get this right before booking treatment — the wrong diagnosis means the wrong product and a wasted callout. If you can't get into the loft safely, a pest controller will identify on the first visit.
Why Cornwall lofts are rat-friendly
The construction patterns matter:
- Cob, granite-and-mortar and stone-built cottages often have multiple soffit and gable gaps from movement and age. Original Victorian and Georgian properties commonly have entry points the original builders never had to worry about.
- Slipping or missing tiles at gable ends, around chimney lead-work and on shallow-pitch coastal roofs. One missing tile is an invitation.
- Generous open eaves — common on Cornish vernacular cottages and 1930s bungalows. Rats walk straight in via the open eave and then drop into the loft void.
- Modern soffit boxes with poorly-fitted plastic boards or vent holes wider than 6mm.
- Climbing access via wisteria, ivy, lean-to roofs, downpipes and trellises. Brown rats are excellent climbers despite their reputation as ground-dwellers.
- Adjacent food sources — chicken runs, horse feed stores, bird tables, fruit trees with windfall, neighbouring composts.
Coastal Cornwall (St Ives, Padstow, Mevagissey, Newlyn, Polperro, Fowey) and rural Cornwall (the Lizard, Bodmin Moor, the Roseland) both see plenty of loft-rat work.
How to know they're rats — the 5-minute confirmation
Before paying for a survey, do this:
- Listen at the access hatch after sundown. Open the hatch, stand on the stair and listen. Rats scuttle, drag, occasionally thump. You'll usually hear movement within 10-15 minutes if there's activity.
- Smell-check. An established rat population leaves a distinctive musky urine smell, sometimes a rotting smell if a carcass is in the void.
- Torch into the loft from the hatch (don't climb in — joists, fragile ceiling boards, and disturbed rats are a bad combination). Look for droppings on insulation, runways (greasy marks where rats follow the same path), chewed insulation balled into nest sites, and chewed wiring sheaths.
- Check the eaves outside in daylight. Look for greasy entry marks around the soffit board where rats have rubbed in and out.
- Photograph droppings on a coin or against a tape. WhatsApp the photo to the pest controller — they'll often confirm species before the visit.
What loft rat treatment costs in Cornwall (2026)
- Standard loft rat programme (2-3 visits, baiting + monitoring): £200-£300
- Rural property with multiple outbuildings: £250-£450
- Severe established infestation (10+ rats, multi-room evidence): £300-£600+ for a longer programme
- Dead rat removal from inaccessible void: £80-£200 if the carcass needs cutting access
- Loft proofing (separate from treatment): £200-£800 builder/handyman, depending on scope
- Insulation replacement (if heavily contaminated): £400-£2,000+ for whole-loft replacement
The treatment cost is usually the smallest line item. The proofing is the one that protects you against repeat visits next year.
How professional loft rat treatment works
The standard Cornwall programme:
- Survey visit. Controller assesses the loft, identifies entry points (almost always more than one), places locked tamper-resistant bait stations or snap traps, photographs evidence, and lists external proofing tasks. CRRU-compliant operators use Second-Generation Anti-coagulant Rodenticides (SGARs) in locked stations only; they do NOT scatter loose poison.
- 10-14 day follow-up. Check take-rate, refresh bait, identify any new activity, reposition stations as needed.
- Clearance visit 10-14 days later. If activity has ceased, the controller writes up the proofing recommendations and closes the job. If activity continues, a fourth visit is normally included.
- Proofing handover. Some pest controllers do their own proofing; many sub it to a roofer or handyman, or hand you a worklist for your own tradesperson.
The CRRU Stewardship Regime, in force from 1 January 2026, requires every professional SGAR user to hold a current stewardship-specific training certificate (less than 5 years old) or be a member of an approved CPD scheme. Every Cornwall controller we refer is compliant.
Why DIY loft trapping rarely clears a real problem
Snap traps and shop-bought bait in a loft sound like a frugal approach. The problems:
- You can't reach the harbourage. Rats nest deep in insulation under joists. Traps on the loft hatch catch the wanderers; the breeding core is untouched.
- Shop bait is weak. Homeowner-grade First-Generation Anti-coagulant Rodenticides are notably less effective than the SGARs professionals use. Rat populations can develop resistance to repeated weak baiting.
- Loose poison is dangerous. Loose grain bait spread in a loft can get washed into wall cavities, eaten by non-target species (owls, family cats, wild birds breeding in eaves), or contaminate water tanks. CRRU rules require locked stations for a reason.
- You can't safely access the void to check. Loft work needs head protection, dust mask, secure footing — and you still can't get under tile felts and around chimney breasts without lifting roof structure.
- Carcasses end up where you can't reach them. A DIY-poisoned rat dies somewhere awkward and starts smelling within 5-10 days. Removing a dead rat from a sealed void is a £80-£200 job in itself.
The honest break-even: if you spend more than £40 on shop-bought traps and bait and it isn't sorted within 2 weeks, you're past the point where professional treatment is the cheaper route.
Proofing — the part that stops them coming back
Loft rat proofing in priority order:
- Find and seal the access point. Almost always the eaves, soffit gaps, missing/slipped tiles, gable vents, or where the chimney passes the roof. A torch survey at dusk often reveals droplets of grease marking the route.
- Wire mesh over gable and soffit vents. 6mm stainless mesh fixed externally; do NOT block ventilation. Cornwall lofts need airflow to manage condensation in salty coastal air.
- Replace slipping or missing tiles. Roofer job, £80-£250 typical for a few tiles plus mortar pointing.
- Brush strip the loft hatch from below if it's a known indoor-to-loft route.
- Cut back climbing routes — wisteria, ivy, overhanging tree branches within 1m of the gutter line. Rats will use these.
- Block any cable/pipe penetrations through the loft floor with wire wool + sealant.
Insulation — replace or treat?
A lightly-contaminated loft (a few droppings on top of insulation, otherwise clean) doesn't need full insulation replacement. The pest controller will recommend bagging and disposing of any obviously soiled material and treating the remainder.
A heavily contaminated loft — sustained rat activity for months, nesting visible, ammonia smell on entry — usually needs the insulation removing and replacing. Expect £400-£2,000+ depending on loft size, access and the type of insulation. Add the disposal cost (contaminated insulation is mixed waste, not standard household).
The legal bit on dead rats and disposal
Dead rats from a domestic property go in the standard household waste — double-bagged, ideally in the wheelie bin not the recycling. Wear gloves. Don't bury (UK regulations restrict burial of dead vertebrates because of disease transmission risk, particularly Leptospirosis carried by rats). Don't compost.
Commercial properties have additional documentation requirements; the pest controller handles disposal under their Animal By-Product paperwork.
When loft rats are urgent
Most loft rat problems can wait the 3-5 working days for a survey. Escalate to urgent if:
- You can smell a dead rat (carcass needs locating fast before the smell pervades)
- Wiring chew damage is visible (fire risk)
- Water tank or pipe damage is suspected (rat-chewed plastic CWS pipes flood lofts)
- Holiday let with imminent guest arrival
- Food business premises
Get matched with a Cornwall loft rat specialist
Drop your postcode on our quote form and mention "loft rats" in the notes. We'll match you with a CRRU-compliant Cornwall pest controller with loft and roof access experience. See related: prevention guide, squirrels in the loft, rat control service, Bodmin, Launceston.