Jemima Lewis: Our pets reflect our lingering love of the wild

I have grown accustomed to waking up with my nose clamped between his sharp, fishy teeth

A word of warning: it really isn't practical to live with a raccoon. Back in the 1930s, when exotic pets were all the rage, the author Cyril Connolly tried it. A friend who had been travelling in South America brought him back a coatimundi – a form of tree-dwelling raccoon with a probing, upturned nose, sharp teeth and a hopelessly undomesticated personality.

The creature, named Kupy, caused such havoc on the flight that mutinous passengers threatened to hurl it out of the window; and once ensconced in Connolly's Kent cottage, its behaviour did not improve. It swung from the rafters, uprooted Connolly's beloved shrubs, rampaged through his dinner parties, smashed his china, chased him around the house and then insisted on sharing his bed, nipping him on his tenderest parts whenever it was threatened with eviction. Eventually Kupy's wild behaviour proved too much for even this most forgiving of animal lovers, and it was packed off to a zoo in Ilfracombe.

A similar fate, I fear, awaits many of the animals that have just been declared legal to keep as pets. Under a shake-up of the Dangerous Animals Act, 33 new species have been deemed sufficiently harmless to serve as domestic companions, without the need for a licence.

Of course, "harmless" is a matter of opinion. The Dangerous Animals Act was introduced in the 1970s in order to protect us from fierce predators roaming the streets. MPs were moved to act, apparently, after a woman in a leopard-skin coat was pounced on by a pet lion called Shane, while strolling through Worthing. None of the 33 species newly cleared for ownership is likely to pose much threat to innocent promenaders in our seaside towns. But introducing one to your home may well have harmful consequences for domestic harmony – not to mention your soft furnishings.

Sloths are said to be terribly grumpy, and their fur isn't nearly as soft as it looks. Raccoons – even the more common American kind – are prone to fits of aggression, and disgraceful scavengers. (Unusually for quadrupeds, they can open dustbins with their thumbs.) Squirrel monkeys behave in ways that might shock the neighbours: they massage urine into their fur, and compare penis size to establish dominance. (The females have pseudo-penises, so as not to miss out on the fun.) The needle-sharp quills of the porcupine are clearly not child-friendly; guanaco llamas need a very big garden (they can run at 35 miles an hour); and even the gentle binturong – a tree-dweller from south-east Asia which chuckles to itself when happy – can be vicious when cornered.

Nevertheless, there will be some people who cannot resist the call of the wild. For the human urge to cohabit with animals, however unsuitable, is stronger than reason. In the wealthy, urbanised West, most people no longer have any practical need of pets: mice and rats can be dispatched by the council, and the average dog will never be called upon to hunt for anything more taxing than a hidden Bonio.

Yet the more useless and inconvenient pets become, the more we dote on them. Dog owners cheerfully scoop the poop in return for the dubious honour of being loved by a creature for whom devotion is merely a genetic imperative imposed by centuries of inbreeding. Cat owners subject themselves to the opposite humiliation: for ever courting the affections of a companion whose glassy eyes reflect back, all too often, only crushing indifference; and who – as Wittengstein observed of lions – we probably wouldn't understand even if they could talk.

To own a pet is to enter voluntarily into a life of bafflement, toil and even physical suffering. My father used to have a recurring nightmare that he was being forced to walk across broken glass. It turned out to be caused by the cat, Dolly, sharpening her claws on the soles of his feet.

My own cat, George, has kept me in a condition of domestic servitude for 13 years. I have grown accustomed to waking up with my nose clamped between his sharp, fishy teeth whenever he wants a midnight feast; or to the sound of him slurping from the glass of water by my bed. (No other receptacle will do.)

And yet this unruly behaviour – this stubborn streak of jungle ancestor – is often what we love most about our pets. A dog chasing its tail, or a cat mysteriously springing into the air as if electrified, delights us precisely because it is so inexplicable.

The further we get from the natural world, the more we crave a break from the homogeneity of humanity. We need to be reminded that we are part of something bigger, more various and unknown than our own society. It is surely no coincidence that there are more tigers in America than anywhere else in the world.

Keeping wild beasts captive may not be the best way to express our fascination, but it does at least denote a lingering desire to be connected to the natural world. We need pets to save us from our civilised isolation. Or as the American Indian Chief Seattle once put it: "If all the beasts were gone, men would die from a great loneliness of spirit."