Early each morning last month we would watch a family of grey squirrels scampering up the trees on the village green and dancing along the walls of our neighbour who, if she had opened the curtains, would have shaken her fist. Where I see a furry little creature more agile than Olga Korbut, others see pests who devour food left for the birds. Rats with tails, some call them though I don’t see the similarity myself. One humane friend managed to cage a particularly voracious culprit and climbed to the top of the Eildon hills, where he let it loose. The beast was back at base, feasting on the bird table, long before his captor reached home.

On a recent trip to the Moray Firth, I heard about a sighting of a grey squirrel near Elgin, which was believed to have smuggled itself in, like Jason Bourne, on the back of a lorry. No big deal, you might think, but in these parts the red squirrel is better protected than the royals at Balmoral. A hit squad was despatched to find and eliminate the intruder, which they did within 48 hours.

The grey squirrel, a 19th-century import from America, has a terrible reputation, thanks to its impact on its native red cousin. Culling is usually considered the best solution and, for the sake of the red, which is particularly susceptible to disease carried by its relative, I wouldn’t argue with that. Less grisly but more final are attempts at the Roslin Institute in Edinburgh to alter the DNA of female greys to render them infertile. If that works then they’ll soon disappear forever, hopefully leaving To Let signs encouraging reds to return.

No such fanciful nonsense in the scientific world, of course. An ecologist at Edinburgh Napier University has pointed out the double standards involved in public attitudes. Whereas the grey squirrel has conservationists reaching for guns and traps, another “invasive alien species” – the domestic cat – is so beloved, there are an estimated 11 million in the UK.

Ecologist Dr Jason Gilchrist, writing on the academic website The Conversation, says: “It is often argued that killing grey squirrels is justified as they predate bird nests. They do, and so do red squirrels, but there is scant evidence that squirrels have a significant impact on songbirds. While domestic and feral cats decimate songbird populations, they are unlikely to be targeted for culls any time soon... In terms of the ecological damage they do, the impact of both species is similar: they don’t belong here and are having negative effects on wildlife.”

While this doesn’t emphasise the potentially irreversible effect of greys on red squirrels, he has a point about predatory cats. They kill about 27 million wild birds every year. It would be a horrifying tally if these were all healthy young things but the RSPB says the majority are either sickly or weak and would soon have expired anyway. Cold comfort for those of us clearing the crime scene where a fat wood pigeon has gasped its last. Nor do I entirely believe it. Watching a black tom motionless as a gatepost beside our chirruping beech hedge, it’s easy to see how a healthy robin, fooled into thinking it was a shadow, could be caught unawares.

Even the most besotted owners squirm at the trophies dropped at their feet – often not entirely dead – and while it’s good to keep down rodents, disposing of feathered carcasses tucked in your slippers is no fun. I say this as a cat person. So far as I’m aware, the only thing my city cat ever caught was a mouse, which I managed to rescue and put back on the street. My cat used to sleep like a Russian fur hat on my pillow, and when she died it was little short of heartbreaking. But now I have a garden, with a hedge that quivers with sparrows and finches, I couldn’t possibly replace her. It would be like tossing a live grenade onto the lawn. It’s in cats’ nature to kill, and other than keeping them confined indoors, or hanging a bell as loud as Big Ben around their neck, they will inevitably go on carnivorous sprees.

Dr Gilchrist is well aware that his comments might outrage the feline-owning community. His aim, he says, is simply “to bring some logic and consistency to the way we treat animals.” The problem is, there’s nothing logical about the love cats inspire.

Pointing out the savage heart that beats within every sweetly purring tabby, for instance, makes absolutely no difference to the cooing and clucking around their every move. Ian Fleming knew what he was doing when he placed a cold-eyed white Persian in his villain Blofeld’s arms. It was hard to tell which was the more sinister, each, as he implied, being utterly deadly. More recently, the costume designers and make-up artists for the film version of Cats were way off the mark. Turning one of the most alluring and lithe species into a creepy hybrid with long legs, flapping arms and a human body completely misses the essence of the feline kingdom. Whether it’s a Siamese or a tortoiseshell, a Bengal or a Manx, elegance is key. Much of the allure lies in their aesthetic appeal and the dignity and hauteur with which they behave. It’s no wonder the Egyptians treated them as Gods. Nor that they were considered an essential accessory for a witch’s diabolical work.

Whereas squirrels might be impressively athletic and undeniably cute, they cannot compete with the fascination cats hold. This arises in part from their disturbingly dual personality. Unlike dogs – what you see is what you get – they are mysterious and ungovernable. As they lie on your lap, exquisitely lovely and touchingly affectionate, they make people feel special. There’s a sense of pride in being favoured by a sharp-toothed beast with vicious claws that, when it slips out of the window flap at midnight, turns into a merciless killer, and by day treats the garden like ScotRail’s buffet trolley.

As anyone who dares suggest cats are a nuisance will soon learn, in this country they are all but sacred. When it comes to choosing between the fate of felines or songbirds, it’s very simple: two legs good, four legs infinitely better.