A pest expert tells us how to deal with monster rats

Harriet Green
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A giant rat, dubbed “Ratzilla”, has shocked the inhabitants of Stockholm.

The 40cm whopper (plus tail) horrified a family - and even their cat - when it took up residence in their kitchen, before meeting its end in a trap.

Curious as to how likely such an experience is in London, and what one should do when faced with a Dachsund-sized rodent adversary, we spoke to David Cross, the head of Rentokil’s Technical Training Academy.

For starters, and just to confirm - Ratzilla was pretty big: “Bigger than anything I’ve seen”, assured Cross. Most rats, he explains, are about 25cm long (not including their tail) and weigh around 250g.

How do they get that big?

The biggest rats are found near animal feed units. The proteins designed for bulking animals for slaughter have the same effect on the grazing intruders. Cross has come across animals that have reached 400-500g. So not quite as big as a Dachshund, which averages between 3.5 and 5kg.

City rats live predominantly in drains and sewers. This isn’t because they’re dirty, rather, they end up being dirty because the drains and sewers provide why they need, and that’s a source of standing water. They have to drink at least once a day, and about 60ml.

In London, as with any city, the highest rat population will be found in old-fashioned sewers, where it’s easier for them to set up home.

Where do they live?

If you’re wondering which borough has the most rats in residence, it’s the borough known for its enduring rodent problem - Westminster.

Something more upsetting is how many rats there actually are: it’s about equal to the human population - possibly even higher, confirms Cross. But the notion that you’re only six feet away from one - that’s a complete myth.

Rats don’t like to be disturbed, and they need a stable environment to function. That means if you’re in a well-maintained office or residential area, you’re unlikely to come face to face with a furry friend very regularly, and certainly not one of Stockholm proportions.

But contact is a problem, because rats are a major public health concern; they carry Weil’s disease and salmonella.

In spite of this, they're actually quite clean creatures, and exist in something of a catch 22. Having to live in drains for water means they’re always having to groom themselves.

Being nocturnal, they’re very poorly sighted, and most of their sense comes from touch. Sewer filth affects the efficacy of the hairs on their body which are so vital to them - the average rat will spend over 20 per cent of its waking time cleaning itself.

How do you deal with them?

For those that need them, traps and poison are both available to the public. Cross says traps are preferable, because, despite it being harder to get the exact trail of a rat, poison can have nasty consequences if other animals or young children come into contact with it.

Pest control services should be consulted whatever you’re using, though, because both products can be dangerous. The largest rat traps (the kind you’d need to deal with a Ratzilla) can take off a human finger.

A plague of rats isn’t a possibility for modern-day London, but that doesn’t mean that other pests don’t regularly infest the places we live and work.

What else plagues the city?

It turns out that ants are one of the main offenders for offices in the capital.

According to Cross, Pharaoh, Argentine and Ghost Ants are a major problem. “They’re very small”, he explains, “less than half the size of a garden ant”. They can also be very pale, adding to their ability to go unnoticed. That means infestation can occur without anyone really noticing - until there are thousand of them.

Exotic spiders, geckos and snakes are also commonplace stowaways - they and the ants are imported on food and commodities. These won’t usually breed, though - it’s just the ants who can thrive in warm and cosy office environments.

It’s also pretty unlikely a monster rat will turn up in London - but then it wasn’t all that likely in Stockholm, either.

Earlier today, a pest adviser in Westminster told City A.M. that, should monster rats arrive in London, the advice wouldn’t really be any different to that for average-sized ones - save the size of the spade you should use, he added.