Large eyes, Micky Mouse ears and bushy tails. It could sound lovely, however that is the pest – with a style for web cables – that’s invading hundreds of houses… and the sounds and smells you have to be careful for: FRED KELLY

The first you’ll know of unwanted guests is the sound of scratching inside the walls. Then, late at night – when they think you’re asleep – you might just hear the scuttling of tiny feet through pipes and crevices.

They’ll be busy chewing through your wiring and gnawing at the wood, but you’ll only truly know who they are when you smell them… the particular sour and unmistakable stench of urine seeping through the brickwork.

The glis glis might have large, round eyes; Mickey Mouse ears; soft, bushy tails and a name so fanciful it could have been dreamt up by Walt Disney himself, but these exotic creatures are far from this year’s must-have soft toy.

Compared with Beanie Babies, Jelly Cats and Labubus, the living, breathing glis glis – with their razor-sharp teeth, prolific birthrate and insatiable appetite – are an all-too-real and entirely unwanted proposition.

And over recent months, with the country caught between cold snaps and deluges, armies of the little-known rodents (‘glis glis’ is the formal Latin name) are besieging homes in search of warmth and shelter.

Once considered a delicacy in ancient Rome, the glis glis – or European edible dormouse – was brought to Britain more than a century ago by an eccentric zoologist before escaping into the wild to become Britain’s most unlikely domestic pest.

So destructive are they that one victim (my colleague Alexandra Shulman) described them as ‘the Terminator dressed up as Bambi’ in yesterday’s Mail on Sunday.

It is also an extremely expensive problem to remove, more of which later. With bodies measuring more than seven inches in length and tails – partly detachable in case of attack – adding up to a further six inches, glis glis are unmistakably larger than house mice.

They can weigh up to nine ounces, live for up to eight years and a female can produce 11 offspring in a single year.

For the moment at least, the edible dormouse is found almost exclusively in the well-heeled Chiltern counties of Berkshire, Buckinghamshire, Hertfordshire and Bedfordshire. But they are spreading, with one giant nest found as far afield as London.

And for residents, it’s a crisis that has been brewing for some time. In 2012, pest controllers in the Chilterns were reporting as many as seven call-outs a day to deal with the vermin problem blighting the area.

In 2018, estimates put the number of the rogue rodents at about 23,000 – and climbing. In one home, as many as 145 glis glis were found living together, scampering around in a pile of their own faeces and hunting desperately for food.

But the true scale of the problem was only brought home in the summer of 2023, when more than 10,000 homes and businesses lost internet connection in the Hertfordshire town of Tring for days. Some thought rats were to blame; others suspected water damage or a problem with the power grid.

No one suspected that ‘cuddly’ glis glis had chewed through wire ducting, outer casings and multiple communications wires in what the signal provider described as an ‘extremely rare’ act of sabotage.

From that day on, the battle lines were drawn.

Today – with reports of home invasions soaring to new highs and one estimate putting the total of glis glis in the Chilterns at more than 30,000 – there is but one question on the lips of Home Counties homeowners, particularly those in older houses with cavity walls: Will they come for me next?

‘I want these f****** gone,’ cried one Reddit user nine months ago in a desperate plea for advice on ridding the rodents from her home.

‘I had my roof done six times,’ replied another user. ‘I had a metal net put over my roof; somehow [they] still got in again. They are a real pain in the a***, especially if there is more than one. They leave a smell that attracts more to come.’

The Mail spoke with Amelia, 46, who lives near Aylesbury with her husband and three children. She confirmed that the glis glis is not just notorious but fabled in her corner of the countryside. A source of both mystery and fear.

‘I grew up here and we used to have ghost stories about the creatures that lived in the chalk hills. Today, people talk about glis glis as though they’re the Loch Ness Monster,’ she revealed, only half joking.

‘We’ve not had them, thank God, but when a neighbour got them down the road, it was like he’d caught the plague. You go to sleep terrified you’ll hear that scratching sound in the roof that everyone talks about.’

What makes the rodents particularly problematic is that glis glis – unlike house mice and rats – are a protected species under the Wildlife and Countryside Act of 1981, meaning they can only legally be trapped, removed or killed by a licensed expert. Quotes vary from £190 to more than £500, depending on the scale of the infestation.

So just how did these vermin – indigenous to the Mediterranean climes of southern Europe – find their way to Britain?

By the age of ten, the aspiring zoologist Lionel Walter Rothschild (a scion of the famous banking family) had already built a natural history museum in his garden shed. 

But unlike most young naturalists of his age, Walter was the son of a wealthy baron with the resources to make his dreams a reality.

Over the course of his life, the 2nd Baron Rothschild – who also became an MP and financier – would introduce all manner of creatures to his Tring Park estate in Hertfordshire, from kangaroos and kiwis to a giant tortoise and a herd of zebras he trained to pull his carriage.

Perhaps nothing had more of an impact than the six glis glis he brought over from Hungary in 1902, however – even if the story of how events played out remains contested.

‘Some of them escaped and started breeding successfully in the wild,’ wrote Rothschild, by then approaching middle age.

‘They have now become a localised pest over an area of approximately 200 square miles in a triangle between Luton, Aylesbury and Beaconsfield…’ But the Baron’s justification may well have been mere distraction. 

For according to Sir Christopher Lever, an author and natural historian, the glis glis were ‘turned loose’ by the entitled collector. Either way, Rothschild was oblivious to the true extent of the havoc he had unleashed.

The chaos continues to blight the Chilterns nearly 90 years after his death in 1937.

Not that glis glis have always been a menace. Look now on your bookshelf, somewhere between Jamie’s 15-Minute Meals and Mary Berry’s Baking Bible, for a copy of the fourth-century Roman cookery book De Re Coquinaria – Latin for ‘On the Subject of Cooking’.

Turn to chapter nine and you’ll find the Roman chef Apicius’s recipe for ‘glis glis’, a delicacy in ancient Rome enjoyed only by the wealthiest, not least because the dormice were reared in captivity and fed an expensive diet of rich, fatty foods before slaughter.

‘Stuff the mice with minced pork,’ writes Apicius. ‘Likewise with mouse meat from all (fleshy) parts of the mouse ground with pepper, pine kernels, laser and garum (or broth). Sew the mouse up and put on a tile on the stove. Or roast in a portable oven.’

Almost 2,000 years on, it seems that attitudes have hardened.

In Germany, glis glis are known as the ‘Seven Sleeper’ because they typically hibernate for seven months of the year between November and May.

Indeed, for thousands of households in England who may not know they have a problem, there’s a nest of glis glis just waiting for the warm weather to wake them from their slumber. And one thing’s for sure: they’ll be hungry.