Our intimacy with rats

At the time of writing, the fishing trawler Spinningdale is still caught on the rocks near to Village Bay, the only landfall on the Hebridean island of St Kilda. The National Trust of Scotland, which owns the island, has launched an “emergency procedure” to deal with the consequences of the shipwreck: baiting traps. Yes, you read me right: baiting traps. The 14-strong Spanish crew were speedily rescued from the stricken vessel, which ran aground during the storms on February 2, but there’s considerable anxiety that some of the Spinningdale’s probable stowaways may get ashore, and if even one pregnant Rattus norvegicus does take the plunge successfully, the outlook for St Kilda’s half million seabirds is pretty grim.

In theory, an incestuous ratty mummy and daddy can produce as many as 15,000 living descendants within a year. And on St Kilda, these frantic gnawers will have a veritable smorgasbord laid out for them on the springy turf – albeit one heavy on the raw egg. For the St Kildan petrels, fulmars, puffins and guillemots have no resident predators, the only native mammal being a subspecies of mouse. As Susan Bain, the trust’s manager affectingly put it, after four bad breeding seasons, the birds “really don’t need another stress”.

Of course, there is an irony cruising even these remote waters, 50 miles due west from the Isle of Lewis. St Kilda supported a human population from the Neolithic era until the 1930s, when the final remnant were evacuated to the Scots mainland at their own request. The St Kildans, unmolested by rats, lived in a strange and communistic Arcadia, where, for generation after generation, they harvested the seabirds from the island’s spectacular cliffs. So, as one land-based predator has quit St Kilda, now, after a 70-year moratorium, another one may be about to pitch up.

That Rattus norvegicus is itself parasitic on human populations adds another twist to the double spiralling of eco and system. I well recall, somewhere in the feverish slumber of a childhood illness, listening to an apocalyptic piece of afternoon theatre on Radio 4. In this play, a mad multi-millionaire fearing the coming Armageddon, retreated to a nuclear shelter on his private island, only to discover that he had brought rats with him, and that they were intent on devouring his carefully selected breeding pairs of humans.

Rats, islands, humans. In Konrad Lorenz’s masterly book On Aggression, the maverick ethologist writes of a Danish island where two rival “tribes” of brown rats had fought themselves to a standstill, occupying exact halves of the available territory, complete with a “front line” of burrows and runs. The possible fate of St Kilda is further illustrated by the incursion of rats to the even more distant Campbell Island, a New Zealand possession near the Antarctic Circle. Brought by 19th-century whalers, the little bastards did for all the native bird-life, including a rare flightless teal. In 2002, the Kiwis struck back, sending 120 tons of rat poison to the island, and killing an estimated 200,000.

The 200,000 figure is interesting, because 250,000 was the number of rats estimated to live in New York in 1949 by the charmingly named Dave Davis, who dedicated his life to their demography. Davis was intent, in part, on debunking the – in his view – preposterous, and oft-quoted, “statistic” that there was one rat per person in urban environments. This shibboleth – which in our own day has morphed into the often stated “you’re never more than 10 feet away from a rat” – in fact derives from a 1909 English study, The Rat Problem by WR Boelter. Boelter based it on the “reasonable assumption” that there was one rat per cultivated acre – he thought it absurd to factor in urban environments.

Forty million acres – 40 million rats and coincidentally 40 million people, a nice parity, and ever since, the idea that we all have a toothy little doppelganger has gnawed away at us relentlessly. The intimacy with rats implied by saying that you’re never more than 10 feet away from one is a kind of Mockney machismo: a tough-guy act in the pointy face of a creature certainly less prevalent – because constantly poisoned – and definitely wholly unaware of our bravado.

Which leads us, messily enough, to Ralph Steadman, who baited me with this rat [see the Independent February 16 2008 issue], together with the following observations: “It’s a picture of rampant hope beneath the boards … and if you’re asking, yes, the rat came from under the boards of the lounge, and had practically fossilised in the balletic pose as though it were defiant in death. It probably died in 1887 when the Old Loose Court was restored. I imagine the house surrounded by hop fields and begging peasants who would empty your cesspit with a shovel and wheelbarrow for sixpence and a clout round the ear. Now look at us! Consumed by living greed and cargos of rats …”

No man is an island – but Ralph gets close.