Glis glis removal in the Chilterns
Scratching, thumping and running in the loft at night, chewed cables or shredded insulation, and an animal like a small grey squirrel with big dark eyes: in the Chilterns that is very often glis glis, the edible or fat dormouse.
Britain's only established glis glis population lives in the Chilterns and the woodland around them, mostly within about 35km of Tring. That is exactly where our glis work is: JG Pest Control has completed 225 glis glis jobs since 2023 across 41 postcode districts, 90% of them in the Chilterns. Our busiest districts include Gerrards Cross, Beaconsfield, Chalfont St Giles, Great Missenden, Berkhamsted, Stoke Poges, Chesham, Rickmansworth and Amersham.
Controlling glis glis is regulated. JG Pest Control is registered with Natural England to use the class licence to trap edible dormice, and our technicians hold the RSPH (BPCA) Level 2 Award, with trainees working alongside qualified colleagues. We are open every day except Christmas Day, early until late.
Signs of glis glis in your loft
Glis glis, squirrel or rat?
Glis glis are often mistaken for grey squirrels or rats. These are the quickest ways to tell them apart:
Glis glis. Grey-brown fur, a bushy tail, large black eyes with dark rings, a body of about 12 to 17.5cm and a tail of about 10 to 15cm. Active at night, and heard far more often than seen.
Grey squirrel. Noticeably bigger, with a fuller tail, and active in the daytime. Squirrels in a loft are usually heard at dawn and during the day.
Rat. A long, thin, scaly tail and no bushy fur on it. Rat droppings, runs and gnawing tend to be at lower levels as well as in the loft.
The glis glis year
- Winter. Glis glis hibernate through the winter, often underground but sometimes in buildings.
- Late spring. They wake and become active again, mostly at night.
- Summer. They feed in the tree canopy and use lofts and roof spaces to nest. The young are usually born in August.
- Late summer to autumn. They feed heavily to fatten up before hibernating, and this is when lofts are busiest and noisiest. Most of our glis glis jobs come between July and October.
The law on glis glis control
Glis glis are not native to Britain, but that does not mean anyone can deal with them any way they like. In England:
- Trapping them requires registration under Natural England's class licence to trap edible dormice before any trapping starts.
- They are listed on Schedule 6 of the Wildlife and Countryside Act 1981, which restricts the methods that can be used to trap or kill them. Under the licence only suitable live-capture traps, covered to keep out daylight, or specific approved spring traps set in a tunnel may be used. Ordinary rodent traps and poisons cannot be used for them.
- Every trap must be checked at least once a day.
- A captured glis glis must not be released. They are listed on Schedule 9 of the Wildlife and Countryside Act 1981, so releasing one is an offence, and it must be humanely dispatched.
- Captures are reported to Natural England every year.
Getting this wrong can be a criminal offence, which is why glis glis control is a job for a registered technician.
How we remove glis glis
- Survey. We confirm it is glis glis and not squirrels or rats, and find where they are getting in and nesting.
- Trapping. We set permitted traps for glis glis in the loft or roof space and check them as the licence requires.
- Proofing. We advise on blocking the gaps they use at the eaves, roofline and around pipes, and on cutting back branches that touch the house.
- Follow-up. Glis glis return to the same buildings, so we plan follow-up visits through the active season where they are needed. Our glis glis work is backed by our guarantee.
Find out more
Frequently asked questions
They are not a native species, but the law still restricts how they can be controlled. They are listed on Schedule 6 of the Wildlife and Countryside Act 1981, so only licensed methods may be used to trap or kill them, and on Schedule 9, so a captured glis glis must not be released.
Only if you are registered under the class licence and use the traps it permits, checking them every day. Releasing one is an offence. For most homeowners a registered technician is the safe and legal option.
Lofts and roof spaces near woodland give them a warm, dry place to nest close to the trees they feed in. They get in through small gaps at the eaves and roofline, often from overhanging branches.
From late spring to autumn, mostly at night. Loft problems tend to peak in late summer and autumn, when they are feeding heavily before hibernation, and the young are usually born in August.
Yes. They gnaw timber, plastic and electrical cables, shred insulation for nests, and contaminate stored items with urine and droppings.
Often, because they return to the same buildings. Trapping combined with proofing the gaps they use, and cutting back branches that touch the roof, is what stops a repeat.
Guides & Advice
Roy Couch is the Technician Manager at JG Pest Control, leading the technician team across the UK. He holds the BPCA Diploma and the RSPH Level 2 Award in the Safe Use of Aluminium Phosphide, and is qualified in the Safe Use of Rodenticides.
Peter Bowers-Davis is a board volunteer at the British Pest Control Association (BPCA), the UK trade body for professional pest management. He works across the Tyro UK group of companies, including JG, setting technical standards, treatment protocols and training programmes.