With a reputation for spreading disease and for damaging foodstuffs, the Common Rat is regarded by most people as little more than a pest. Point out a rat to the wrong person and not only will they utter the most disparaging of responses, but they might even shudder and take a subconscious step backwards. Of course, our problem with rats is just that; it is ‘our’ problem and of our own making. We have cast the rat as villain because it interferes with (or is perceived to interfere with) our way of life.
There is no doubt that rats do damage foodstuffs, such as grain stored on agricultural premises, but if we are going to harvest and store food in this way, then we should not be surprised when some other creature exploits the opportunity being offered. Interestingly, the damage to foodstuffs comes primarily from contamination (with faeces, urine and hair) rather than from consumption, and rats do surprisingly little damage to the standing crop. Control measures tend to be focussed on killing rats or deterring them, rather than on the logical (though more expensive) option of properly excluding them from where we store our food. Rats also spread disease, notably leptosprirosis, but the risks to us are small relative to the other risks that we face in our daily lives.
Much of our problem with rats comes down to perception. The Common Rat is perceived as an invader, the aggressive Seventeenth Century colonist that ousted our ‘native’ Black Rat (a smaller and more delicate creature), but the Black Rat is itself a colonist (arriving with the Romans). It is also wrongly assumed that the Common Rat arrived here from Norway, an error perpetuated through its scientific name Rattus norvegicus. In fact, the Common Rat did not reach Norway until nearly half a century after it had first arrived here, most likely on a ship out of Russia.
Rats are perceived to be dirty, disease-ridden creatures, in part because of their association with the underbelly of society. Rats do well in urban areas; they establish colonies in our sewers, on the underground, alongside our inner city rivers and around our refuse tips. But this says more about us, about the rubbish and the waste that we create. The rats I see most often are those that inhabit the banks of the river running through town. These rats feed on the waste food dumped by passers-by, too lazy or ignorant to take their waste home. We have become a disposable society and it is our excesses that support the rats that we transported across the globe in our ships. Perhaps their presence says more about us than it does about them.