Are we dropping the rat race? How rodents took over our places of work | Science

An empty office building is a good place to shelter if you’re a rat in a crisis. It will be warm and dry and, if you’re lucky, one of the humans who hastily vacated before the last coronavirus lockdown will have left a half-eaten Pret flapjack in a drawer for you. Not that you’re fussy. The loss of your usual diet of commuter leftovers is a blow, but it’s not insurmountable. “Rats will always find something to eat,” says Richard Ashley, emeritus professor of urban water at the University of Sheffield. “Human waste is ideal, but any natural organic material will do. Houseplants are fine. Leather will do at a push.”

You can usually find a way in via the toilets. As a rat, you’re neophobic, which means you don’t like going places where you don’t feel safe. This makes you both hard to trap and unlikely to pop up while a human is actually sitting on the loo, much to the human’s relief. However, if an office is left empty with the central heating on, the water in a U-bend can evaporate and it might be worth risking the vertical migration from cold sewer to warm corporate setting.

“A rat can climb up a wastewater pipe, no problem,” says Andy Tyson of Guardian Pest Management in London. “If no one’s there using a toilet and flushing a cistern, rats can come out.” This is a particular problem in modern office buildings, he adds, where wastewater pipes are usually made of plastic and encased within walls. “Rats can gnaw through plastic. Not often, but they have done it and you can tell. But it’s a real problem finding it and no one I know has a perfect solution to it.”

And once inside, you and your rat family will find the modern office environment has many convenient nesting sites. “You know those horrible ceilings you get in offices – those square tiles that you move and you can never put back straight?” says Rick Young, a pest controller from Manchester. “That’s one of the key locations for rats. Full of lovely wires to chew.” He was once called to a sports shop where a rat had fallen through this liminal zone on to a customer. “Rats are pretty heavy,” he adds, “so you’re going to know about it.”

‘When we’re scared, we tend to think rats are taking over.’ Photograph: Getty Images/iStockphoto

For many of us resigned to working from home, those office spaces that we inhabited day in day out, year after year, and then abandoned suddenly last March are an increasingly distant memory. It’s hard to imagine any form of life at all existing between those empty desks and black computer screens. Yet in the year since we’ve been gone, a different form of life is creeping in, making the most of our absence.

During lockdown, the British Pest Control Association has reported an increase in rodent sightings of more than 41%. “We’ve had reports of rats and mice infesting empty buildings and it seems that their lifestyle patterns are changing,” says BPCA spokesperson Natalie Bungay.

Since our cities and towns emptied out and there’s less food discarded in outdoor spaces, rats are more tempted to come inside. As one office worker who still cycles in part-time says: “Our office is designed for 500 people and it’s steadily gone down to 50, 20, 10 of us. It’s full of mouse and rat traps now. Recently a mouse scampered over my desk while I was sitting there. And one of my colleagues went into the gents and saw a live brown rat flopping around in the bowl of the loo like a seal. He let out a yelp, pulled his trousers up and shot out in horror.”

Once a week, he says, the cleaners now turn on all of the sinks and showers full-blast to flush out the rats. “It does make you think that when we’re not there, the rodents are all running around making themselves at home.”

For other lone office workers, the odd mouse sighting has been something of a novelty: “When there were a few of us in before Christmas, it used to scuttle under our desks and we’d leave a few crumbs of cake out for it. I think they’re bolder now that there are fewer of us around.”

Pest controllers warn that unless business owners take sensible precautions, rats and mice will make merry

Pest controllers warn that unless business owners take sensible precautions, rats and mice will make merry. According to the January ONS figures, 27% of businesses in the UK have closed or paused trading due to the Covid-19 pandemic, while only 48% of workers had travelled to work in the previous seven days. “Large office spaces – any commercial space that usually gets a lot of footfall, like hairdressers, pubs, shops – can become a breeding ground,” Young says. Pest.co.uk warns the British rat population boomed by 25% in 2020, bringing the total to 150m. And owing to the speed with which rats breed, a minor incursion that is not dealt with fast can soon become a major infestation. If you return to the office after lockdown and discover Rattus norvegicus has learned how to use Excel, taken over the executive suite and restructured your company… Well, consider yourself warned.

There is something end-times about rats – a deep association with plague, squalor and apocalypse that gnaws at the modern human psyche. During the first spring 2020 lockdown we were treated to a series of diverting stories about nature returning to our abandoned city centres: dolphins were (falsely) reported to have returned to the Venice canals; cougars roamed apartment complexes in Santiago; wild boars probed bins in Haifa; goats wandered around downtown Llandudno. But rats are in a different category, something other than wildlife – the undocumented migrants of the animal world. In this grimmest phase of lockdown, stories of nature returning to cities tend to have a hysterical tone. The Sun is already warning of “RATMAGEDDON” in 2021 as “MUTANT RATS” invade our homes and offices.

“There’s nothing good about rats,” complains Mohammad Hanafi, a technician with Pest Control Service Group. “All they do is mate, breed and cause damage.” He was recently dispatched to a call centre that had been destroyed by rats entering via an air vent from the kitchen. A rat’s incisors never stop growing, he tells me, so they will gnaw through anything to wear them down. “Internet cables. Keyboards. Anything they see. That’s where the word rodent comes from: the Latin word for gnaw.”

But rats have never had a good press. They are instruments of torture in George Orwell’s 1984; the embodiment of pure evil in HP Lovecraft’s wonderfully nasty story The Rats in the Walls; and one medieval writer wrote that they were so depraved, their urine caused flesh to decay. It was only with the advances in public sanitation in the 19th century that rats came to be linked with plague, disease and squalor – but even before then, rats were detested for their fecundity. A female rat becomes sexually mature at 12 weeks, produces litters of around eight rats, and will mate again within 48 hours of giving birth. According to Rentokil, in optimal conditions two rats will become 500m rats within three years – though you would need an enormous laboratory to recreate these “optimal” conditions and, well, Rentokil would say that. Its shares are up more than 16% year-on-year.

Rats giggle when tickled. Experiments on them have located the ‘tickle centre’ in mammal brains

Hanafi is not alone among pest controllers in speaking of his quarry with something approaching awe. He tells me that rat incisors will grow up to half a metre – in reality, they would starve to death long before it ever got that bad – but it is true that in addition to being able to slither round a U-bend, rats can survive a 50ft (15m) drop, tread water for three days and hold their breath for three minutes. They giggle when tickled; experiments on rats have located the “tickle centre” in mammal brains. Their teeth are harder than iron, and their bite is six times stronger, relative to their size, than that of a great white shark. “When a rat’s bite touches the bone, it makes you faint in a minute, and it bleeds dreadful – ah, most terrible – just as if you had been stuck with a penknife,” reported Jack Black of Battersea, the rat-catcher profiled in Henry Mayhew’s London Labour and the London Poor. Black anointed himself ratcatcher to Queen Victoria and sold a couple of pedigree “fancy rats” to Beatrix Potter.

Rats are clever, too. Extremely clever. A trap is nothing to the older, more experienced rats, an exterminator told the journalist Joseph Mitchell in his classic New Yorker essay, “Rats on the Waterfront”: “They just kick it around until it snaps; then they eat the bait. And they can detect poisoned bait a yard off. I believe some of them can read.” Young says he once saw a rat pause at a glue trap that had been laid in its path, return to the bin it had just come from, and fetch a crisp packet to stick over it, meaning it could pass with ease. “I think they’re a fantastic rodent,” he says. “Not just because they provide me with a living. But everything tries to kill the rat. When you think about how much they pack into 12 months of life, you gotta have a bit of respect for them.”

However, as Natalie Bungay counsels, it’s not as if the rats are enjoying this any more than we are. The disruption to their established routines has been profound and the closure of restaurants has hit them particularly hard. “There’s less rubbish on the streets for them to eat. But because of the vacated spaces, there’s more space for them to occupy. They have to forage much further and make do with other types of sustenance. In the early lockdown, many local authorities were taping up bins. Those rats will be going further afield and appearing in areas we wouldn’t normally see them.” In the end, rats just want what we want: food, warmth and a place to have families.

As Jonathan Burt writes in his excellent book Rat – part of the Reaktion series on animals in culture – our phobia of rats is intimately tied up with our own self-image as humans. We despise rats for the very things we despise in ourselves: their filth, their lust, their disease, their destruction, their pointless, unbounded, never-ending consumption. Their ingenuity. Their hypocrisy – rats make everything else dirty but keep themselves extremely clean. Rats, he argues – not apes – are what humans fear we will devolve into in the event of societal collapse. Burt quotes the 1930s bacteriologist Hans Zinsser, who singled out rats as humans’ closest rival as destroyers of life. “Neither of them is of the slightest earthly use to any other species of living things,” he wrote. “Gradually these two have spread across the earth, keeping pace with each other and unable to destroy each other, though continually hostile.”

The American journalist Robert Sullivan, who spent a year stalking the rats outside his apartment in Manhattan for his classic book, Rats: A Year with New York’s Most Unwanted Inhabitants, came to see rats as humans’ mirror species – an indicator of the presence of man, just as the other creatures returning to cities are indicators of the absence of man. “The way I see it, how we think about rats typically has more to do with us than rats,” he tells me. “When we’re scared, we tend to think rats are taking over the world. When we take a deep breath, we see the world is broken, and rats are there to point us toward some things that might be easily fixed, like poor housing conditions and the public health in general, which has been mostly gnawed away while we’ve been too distracted to notice or care.”

You’re never going to get rid of them – it’s just a matter of maintaining the balance

Those who are longer in the tooth feel the hysteria to be misplaced. “You’re never going to get rid of them – it’s just a matter of maintaining the balance,” says Ashley, who once constructed an enormous model of a sewer and domestic toilet set up and filled it with rats in order to better understand their behaviour. Contrary to popular belief, he says, rats never breed more than the available food supply can support; they also stick closely to family groups. He tells me he ended up hugely impressed by their resilience, their tenacity, their capacity to survive. “Fascinating creatures – completely fascinating,” he says. “I always think that when we’re gone, it will be the bacteria, the cockroaches and the rats that will be left. Whatever the conditions, they would reach a balance.”

But what happens when lockdown finally eases and we have to return to our ghostly offices? Will it be a battle to win these neglected spaces back?

While the guesstimates and warnings of pest control companies should be read with scepticism, clearly the problem is real. “A lot more people are seeing rats when they’re out and about, which is always a warning that numbers are on the increase,” says Jonathan Ratcliffe of Pest.co.uk. “What we’re waiting for is when people do start going back into factories, offices, all the food outlets that have been shut – well, it could be interesting.”

They don’t call it the rat race for nothing.