If you hear scratching or squeaking in a loft and your first move is to call a pest controller, that’s the wrong first call if the noise turns out to be bats. All UK bat species are legally protected, and disturbing, capturing, injuring or destroying their roosts is a criminal offence — which means bats fall outside ordinary pest control and into a specific licensing system run by Natural England, separate from anything a general pest technician is authorised to do.
Why bats aren’t a pest control job
Ordinary pest species can be treated once identified. Bats cannot — every UK bat species and their roosts are protected under UK wildlife law, and that protection applies to the roost itself, not just to individual bats, so it can be an offence to damage or destroy a roost even if no bats are present in it at the time. This is the reason a pest control company that discovers evidence of a bat roost during a job — droppings, staining, or the bats themselves — should stop and refer the situation on rather than treat it as they would rats, mice or insects. Building work that risks disturbing a roost needs a licensed ecologist and, in most cases, a Natural England licence before it can lawfully proceed.
What has to happen before work starts
Because a bat survey can only be carried out at certain times of year — bats are most active and easiest to detect during their spring and summer activity season — anyone planning building work on a property that might contain roosting bats is advised to arrange a survey at the very start of the planning process, not once work is already scheduled. A licensed ecologist typically carries out survey work in stages: an initial scoping assessment to judge the likelihood of roosts being present, followed, where risk is identified, by dedicated emergence or re-entry surveys that record bats leaving or returning to a roost at dusk or dawn. Natural England generally expects this survey evidence to be reasonably current — typically no more than around two survey seasons old — by the time a licence application is submitted, and using older data usually means resurveying rather than relying on a historic report.
The two main licensing routes
Where a survey confirms a roost is present, the route to a lawful licence depends on how significant that roost is. A Low Impact Bat Licence (sometimes referred to by its class reference, CL21) is available for smaller-scale situations: only lower-conservation-status roosts such as feeding, night, day or transitional roosts (not maternity or hibernation roosts), a small number of roosts present — generally no more than three — involving common, widespread species such as common or soprano pipistrelles or brown long-eared bats, and works that are short-term, typically completed within about six months. This route is administered through a registered ecological consultant rather than a lengthy direct application, and registration can, in practice, be completed in a matter of days rather than weeks.
Larger, higher-risk situations — maternity roosts, hibernation roosts, protected species beyond the common ones covered by the low-impact route, or more complex, longer-running works — require a standard mitigation licence instead. That route needs a full application prepared by an ecological consultant, covering a method statement, a schedule of works and supporting plans, submitted directly to Natural England, and it typically takes significantly longer to process — around 30 working days is a commonly cited minimum. A standard mitigation licence application generally also requires planning permission (or an equivalent consent) to already be in place for the works, so it sits at the end of the planning process rather than the start of it.
What happens if bats turn up mid-project
If bats are discovered once work has already started — a roof stripped for re-covering, for example, revealing droppings or bats in the roof void — that is treated as a serious problem rather than a minor delay: work must stop immediately in the affected area, and only a registered ecological consultant or their accredited agents are authorised to handle bats found during works. Contractors and general site staff are not permitted to handle them. Guidance is consistent that continuing works, or attempting to relocate bats without authorisation, risks prosecution, on top of whatever delay and cost the stoppage itself causes — which is the core argument for commissioning a survey before a project starts rather than discovering the issue partway through.
The bottom line
Bats are wildlife, not pests, and UK law treats them accordingly: any building work with a realistic chance of disturbing a roost needs a licensed ecological survey first, and — depending on what that survey finds — either a Low Impact Bat Licence or a full Natural England mitigation licence before work can lawfully continue. A pest control call-out is the wrong first step if bats turn out to be the cause of the noise in the loft.
Sources
- Arbtech, “Low Impact Bat Licence: Definitive Guide for Developers” — arbtech.co.uk
- GOV.UK, “Bats: survey or research level 2 licence (CL18)” — gov.uk