Grey squirrels and the Invasive Alien Species Order 2019

Grey squirrels are an invasive non-native species in the UK, listed under the Invasive Alien Species (Enforcement and Permitting) Order 2019. For businesses this has two consequences: the damage they cause to buildings and infrastructure is significant, and it is an offence to keep, transport or release a captured grey squirrel back into the wild. Control has to be carried out humanely and lawfully.

For a commercial site, grey squirrels are easy to underestimate. They look like a countryside curiosity, not a pest, right up until they are in a roof void chewing through cabling. They are also one of the clearest examples of how invasive species law changes what you can and cannot do. This article covers the damage grey squirrels cause to commercial property, what the 2019 Order requires, and how lawful control works.

What damage do grey squirrels cause to commercial property?

Grey squirrels are rodents, and like all rodents they gnaw constantly to keep their teeth in check. In a building that turns them from a wildlife issue into a structural and fire risk. The problems we are called to most often are:

• Electrical damage and fire risk. Squirrels strip the insulation from cabling in roof voids and risers. Exposed and damaged wiring is a recognised fire cause, and on a commercial site that is a serious liability.
• Structural damage. They gnaw timber, fascias, soffits and insulation, and enlarge entry points so they can return. Loft and roof-void insulation is frequently fouled and destroyed.
• Water ingress. Damaged roofing and displaced tiles let water in, leading to damp, staining and follow-on repair costs that dwarf the original problem.
• Noise and disruption. The scratching and movement in voids above occupied space is enough to disrupt offices, care settings and residential blocks.

Because the damage is hidden in voids, it is usually well advanced by the time it is noticed. That is why grey squirrel control belongs in a managed pest programme rather than a one-off reaction, the same principle we set out across our commercial pest control compliance guide.

What is the Invasive Alien Species Order 2019?

The Invasive Alien Species (Enforcement and Permitting) Order 2019 came into force on 1 December 2019. It enforces restrictions on a list of invasive non-native species of special concern, and the grey squirrel is on that list. For listed species, the Order makes it an offence to keep, breed, transport, sell, use, exchange, allow to reproduce, or release them into the environment.

The single most important consequence for anyone dealing with grey squirrels is the rule on release. If a grey squirrel is trapped, it is an offence to release it back into the wild. The law does not permit catch-and-release. A trapped grey squirrel must be dealt with humanely on site, which means dispatched in a humane manner by a competent person. Penalties for offences under the Order are significant, running up to imprisonment and fines on conviction.

How does this interact with animal welfare law?

This is where competence matters. The 2019 Order means you cannot release a trapped grey squirrel, but the Wild Mammals (Protection) Act 1996 and general animal welfare law mean any dispatch has to be carried out humanely. Those two duties have to be satisfied at the same time. You cannot let it go, and you cannot cause it unnecessary suffering.

For a business, that rules out well-meaning but unlawful responses such as trapping a squirrel and releasing it in a nearby park, and it rules out inhumane improvised methods. The lawful path is humane control by a competent, trained operator who understands both the invasive species rules and the welfare requirements. That is exactly the combination a professional contractor brings, and it is the heart of our commercial wildlife control service.

The combination also has implications for timing and method. Live-capture traps have to be checked frequently so an animal is never left distressed, and any dispatch has to follow recognised humane methods carried out by someone competent to do it. Drowning, the use of unapproved substances, and prolonged confinement are not acceptable and can themselves be offences. This is precisely the kind of judgement that a trained, insured operator is equipped to make and to document, and it is why improvised do-it-yourself control so often strays onto the wrong side of either the invasive species rules or the welfare law, and sometimes both at once.

What should a commercial site do about grey squirrels?

The approach mirrors good rodent control: survey, exclude, and control lawfully where needed, all documented.

1. Survey and identify the access. Establish how squirrels are getting into the void and what is drawing them. Overhanging trees, damaged roofline and open eaves are the usual routes.
2. Proof the building. Seal and reinforce entry points once the void is confirmed clear, so the problem cannot simply recur. Proofing is the durable fix.
3. Control lawfully where required. Where squirrels are present, humane control is carried out by a competent operator in line with the 2019 Order and welfare law, with no release back to the wild.
4. Repair and monitor. Make good the damage to cabling, insulation and roofline, and keep the site monitored so a recurrence is caught early.
5. Document everything. Record the work, the methods and the legal basis, so the activity is evidenced and defensible.

For estates and multi-site portfolios, this needs to be delivered consistently across every location, which is where the discipline in our multi-site and FM pest control approach matters. And as with birds, the legal route is everything, a theme we also cover in our article on bird control licences.

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