About this guide
Grey squirrel pest control requires a legally compliant approach — it is a criminal offence to release a captured grey squirrel into the wild. This guide covers the property damage grey squirrels cause, what professional pest control involves, the legal methods available, and the proofing measures needed to prevent squirrels from returning after a property has been treated.
Why Grey Squirrels Are a Pest Control Problem in the UK
The grey squirrel (Sciurus carolinensis) was introduced to the UK from North America in the 1870s and is now established across virtually all of England, Wales and lowland Scotland — with an estimated population of 2.7 million (Forestry Commission). Under the Wildlife and Countryside Act 1981, the grey squirrel is listed on Schedule 9 as an invasive non-native species: it is a criminal offence to release a grey squirrel into the wild or to allow a captured grey squirrel to escape. This legislation exists because grey squirrels are the primary threat to native red squirrel (Sciurus vulgaris) populations, which number approximately 300,000 — mainly in Scotland and parts of northern England — and grey squirrels carry squirrelpox virus, which is lethal to red squirrels but harmless to grey.
Grey squirrels are diurnal — active during daylight hours — and are strong, persistent and able to gnaw through timber, lead, plastic and standard wire mesh. Once a squirrel has identified a warm, sheltered building as a resource, it will return repeatedly. Squirrel pest control is not a passive deterrence exercise — it requires active population reduction combined with structural proofing to prevent re-entry.
The Property Damage Grey Squirrels Cause
Grey squirrels cause damage in two main contexts: inside buildings (primarily loft spaces) and in gardens and woodland. Inside a building, the damage is often severe and expensive. Squirrels gnaw electrical cables — creating a genuine fire risk from short circuits and arcing — as well as water pipes (flood risk), structural timber including joists and roof members, and roof insulation. Squirrels commonly nest in roof insulation, tearing it apart to build a drey (nest) and contaminating the loft with droppings and urine. A single squirrel returning to a loft over a winter season can cause cable and timber damage requiring an electrician and possibly a structural survey before repairs are complete.
Garden and Structural Damage
In gardens, grey squirrels strip bark from young trees — particularly sycamore, beech, lime and oak — by gnawing through the outer bark to reach the sap-rich cambium layer beneath. Ring-barking (removing a complete ring of bark) kills the tree above the damage point within one growing season. Squirrels also raid bird feeders, destroy ripening fruit and consume significant quantities of seeds, bulbs and newly planted stock. In commercial horticultural, forestry and agricultural settings, grey squirrel damage has significant economic consequences — an estimated £37 million per year in forestry damage alone (Forestry Commission).
Grey squirrel damage to UK forestry is estimated at approximately £37 million per year, primarily from bark stripping of young broadleaf and conifer trees during the vulnerable sap-rising period in spring and early summer.
— Forestry Commission
Legal Grey Squirrel Pest Control Methods
Professional grey squirrel pest control uses a combination of trapping and proofing — and all control work must comply with the Wildlife and Countryside Act 1981, the Spring Traps Approval Order (England) 2018 and the Animal Welfare Act 2006.
Cage Trapping and Humane Dispatch
Live cage traps are the most commonly used professional method for grey squirrel control in building and garden settings. Approved cage traps (single or multi-catch designs) are baited with whole maize and placed on squirrel runs, at entry points, at feeding stations and in the loft space if squirrels are active inside. All cage traps must be checked at least once every 24 hours under the Animal Welfare Act 2006. Every captured grey squirrel must be humanely dispatched immediately — it cannot be relocated and released. Humane dispatch is carried out by the professional technician on site at every trap check. A cage trapping programme for an established building infestation typically runs 4–6 weeks to clear the resident population.
Approved Spring Traps
Spring traps approved for grey squirrel control include the Fenn Mk4, Fenn Mk6, Kania 2000 and other traps listed under the Spring Traps Approval Order (England) 2018. These must be set inside a tunnel of specified dimensions (minimum 230 mm × 75 mm internal, to reduce access by non-target species) and positioned on known squirrel runs. Spring traps kill instantly and humanely when triggered. They are particularly effective on known runs and at building entry points, and require less frequent inspection than cage traps — though regular checking remains essential.
Why You Cannot Relocate a Grey Squirrel — Releasing a live-caught grey squirrel into a park, woodland or any natural environment is a criminal offence under Schedule 9 of the Wildlife and Countryside Act 1981. It is also ecologically harmful — relocated grey squirrels displace and compete with resident populations in the release area and continue to threaten red squirrels through squirrelpox virus transmission. The only legally compliant and responsible outcome for a live-caught grey squirrel is immediate humane dispatch on site.
Proofing — Excluding Squirrels from Buildings
Trapping removes the existing population, but without proofing the structural entry points, new squirrels from the surrounding area will identify and use the same access routes within weeks. A professional squirrel pest control programme includes a written proofing survey identifying all entry points to the building — gaps in the roofline, damaged fascia and soffit boards, gaps where cables and pipes enter through the roof, open ridge tiles and loose tiles. Proofing materials must be robust: heavy-gauge galvanised or stainless steel mesh (minimum 25 mm × 25 mm for squirrel exclusion, securely fixed with appropriate fixings), or solid repair of structural timber defects. Standard wire mesh, timber battens and plastic covers are not adequate — squirrels gnaw through them within hours.
Squirrel Control and Bat Surveys
Before beginning loft exclusion or structural proofing work, a professional squirrel pest controller assesses whether bats are present in the loft space. All bat species in the UK are strictly protected under the Conservation of Habitats and Species Regulations 2017 and the Wildlife and Countryside Act 1981 — bat roosts cannot legally be disturbed without a licence from Natural England, NatureScot or Natural Resources Wales. This assessment is a standard part of professional squirrel control practice. If bats are confirmed or suspected, a licensed bat surveyor is engaged before proofing proceeds. This protects both the client and the contractor from inadvertent offences under bat protection legislation.
When to Call a Professional Squirrel Pest Controller
Squirrel pest control is always better addressed early than late. If you hear daytime scratching, gnawing or scrabbling from your loft, find squirrel droppings in the roof space, notice damage to roof timbers or cables, or observe squirrels accessing your roofline, arrange a professional inspection as soon as possible. The longer squirrels are resident in a building, the greater the damage accumulates. Early intervention — before cables are significantly gnawed or structural timbers damaged — substantially reduces total repair costs. Professional pest controllers in South Yorkshire can inspect, trap, proof and provide written confirmation of control — a complete service to protect your property.
Frequently Asked Questions
Is it illegal to kill a grey squirrel in the UK?
No — it is legal to kill grey squirrels using approved humane methods. Grey squirrels are listed on Schedule 9 of the Wildlife and Countryside Act 1981 as an invasive non-native species, meaning control is not only permitted but actively encouraged. Approved legal methods include cage trapping followed by humane dispatch, spring traps listed under the Spring Traps Approval Order (England) 2018 set inside approved tunnels, and shooting with an appropriate firearm.
The important legal requirement is that any killing must be done humanely in compliance with the Animal Welfare Act 2006.
How do squirrels get into my roof?
Grey squirrels access roofs through gaps in the roofline: rotting or damaged fascia boards where the roof meets the eaves, gaps where the roof tiles or slates sit over the eaves, open ridge tiles at the roof apex, and gaps around cables, pipes and aerials entering through the roof covering. Squirrels are agile climbers — they ascend drainpipes, rough render, timber cladding, trellises and overhanging tree branches to reach roof level. Once a squirrel finds a suitable entry point (warm, sheltered, close to food), it returns habitually.
Early identification and proofing of entry points prevents establishment.
Can I use squirrel repellent products to deter grey squirrels?
There is no peer-reviewed evidence that ultrasonic deterrents, chemical repellents or predator scent products provide reliable, lasting deterrence of grey squirrels from properties or gardens. Grey squirrels are highly adaptable and habituate quickly to sensory deterrents. Physical exclusion — proofing entry points to buildings with heavy-gauge galvanised steel mesh (minimum 25 mm × 25 mm) before squirrels gain access — is the most effective preventive measure.
For squirrels already established in or around a property, active population reduction through professional trapping is the only reliably effective approach.
Do squirrels carry diseases that affect humans?
Grey squirrels in the UK carry squirrelpox virus — lethal to red squirrels but harmless to grey squirrels and humans. They can also carry leptospirosis and other zoonotic pathogens, though the direct public health risk to humans from normal encounters with grey squirrels is considered low. The main risks during pest control work arise from handling live or dead squirrels — appropriate gloves and hand washing are sufficient protective measures for routine pest control activity.
The primary human health concern is indirect: squirrel damage to electrical cables creates fire risk, and structural timber damage affects building integrity if left untreated.
How long does a professional squirrel control programme take?
A professional grey squirrel control programme for a typical residential loft infestation typically runs 3–6 weeks of cage or spring trap deployment, with trap checks at least every 24–48 hours. The programme continues until no squirrels are caught over a sustained monitoring period — typically 7–10 days with active traps producing no captures. After clearance is confirmed, structural proofing is completed and a monitoring visit confirms no re-entry.
The full programme from initial survey to written discharge confirmation is typically 4–8 weeks, depending on initial infestation size and the time required for any structural proofing repairs.
What happens to squirrels caught in cage traps?
Grey squirrels caught in cage traps must be humanely killed immediately — it is a criminal offence under the Wildlife and Countryside Act 1981 to release a captured grey squirrel into the wild or allow it to escape. The professional pest controller carries out humane dispatch at each trap check visit, on site. Approved dispatch methods used by professionals include a swift blow to the back of the skull or CO₂ chamber.
The trapped squirrel is not transported elsewhere and is not released. This legal requirement applies to everyone — householders who self-trap as well as pest control professionals.
Can I keep a grey squirrel I have caught?
No. Keeping a live grey squirrel in captivity is illegal under the Wildlife and Countryside Act 1981 Schedule 9. Grey squirrels cannot be kept as pets, held in captivity, or transported alive except under a specific licence from Natural England (or equivalent authority).
If you catch a grey squirrel in a cage trap, it must be humanely killed on site immediately. If you are unwilling or unable to do this yourself, contact a professional pest controller who will carry out the dispatch at the trap location.
Squirrel Pest Control Across South Yorkshire
Apex Pest Control Ltd provides professional grey squirrel pest control for homes and commercial properties across Sheffield, Leeds, Barnsley and Rotherham — including cage trapping, spring trap programmes, loft exclusion and structural proofing. All work complies fully with the Wildlife and Countryside Act 1981.
Contact Apex Pest Control Ltd for a squirrel control assessment.