A tail of two cities

PUBLISHED : Monday, 11 February, 2008, 12:00am
UPDATED : Monday, 11 February, 2008, 12:00am

Andrew Sze Wai-chun reckons he caught a kindred spirit red-handed - or pink-pawed - in his kitchen the other night. The 35-year-old teacher switched on the light, and there was a rat, as big as a cat, on his countertop.

Some Hong Kong folk might have been startled by the visitor's whiskers, beady eyes and its cheek in trying to unscrew the lid of a peanut butter jar. But not Sze. Born in the Year of the Rat, he knows rodents have creativity, ambition, generosity and the ability to get along well with others.

'We looked at each other for a moment,' Sze recalls. 'I thought, 'Well, he's a rat. I'm a Rat. He likes peanut butter. I like peanut butter. I'll leave him until morning'.'

Sze's midnight pal may have concluded from his experience that it's safer in a Hong Kong kitchen than out on the streets. And he may well be right.

Rodent experts don't know how many rats and mice there are in Hong Kong, but the government's out to get them. The start of the Year of the Rat also marks a tailing off of the first phase of the Food and Environmental Hygiene Department's Anti-Rodent Campaign 2008 in 79 markets before it gets going again in July.

The initiative includes public notices displayed by market stalls, posters tacked up in problem areas such as Kwun Tong and Western, and a contest asking participants to find all the things on a cartoon drawing of a fruit stand that a rat could exploit.

Then there's the rat and mouse traps and poison. The extermination rate in Hong Kong is not tallied, experts say, but the department tries to determine Hong Kong's rodent infestation rate by calculating the amount of bait the animals consume in a given period.

The infestation rate rose to 4.8 per cent last year from 2.9 per cent in 2006 and officials want to see whether it continued to rise, the department says. It was 16 per cent in 2000, it adds.

'The rodent problem is not serious in the territory on the whole,' says Yuen Ming-chi, the department's head of pest control. 'However, there should be no slackening in rodent prevention.'

A greater concern is the 'rat-flea index', as the insects on the rodents have historically caused people more harm with diseases such as bubonic plague. Although Hong Kong has not been infested with the plague since the mid-1920s, the department still uses the index to regulate infestation control efforts and reduce the risks of other rodent-borne diseases such as hantavirus, spotted fever, leptospirosis and various forms of typhus.

Yet even the most stringent campaigns were not going to eliminate a rat population, say rodent-control experts such as Jackson Chan Chak-shum, president of the Hong Kong Pest Management Association.

Without control measures, the animals would take over Hong Kong - and soon, he says. Females are pregnant for three weeks and have up to 12 pups, and about three months later, grand-pups. In a year, one rat couple can produce 15,000 descendants, keeping professionals such as Chan in business.

'You will never get rid of the problem,' he says, 'but you can take it out of sight. That's why it's called rat 'control' and not 'elimination'.'

And thanks to pre-holiday custom of house cleaning, Lunar New Year is the busiest time of the year for his firm, ISS, one of a co-operative of about 80 specialist contractors for the department.

Chan says the problem is not that there are too many rats (they have long outnumbered humans) but that they are too agile to be caught or killed easily and too rapacious to stay away from things they want.

Catchers know that a rat is a formidable quarry that can fit through any opening the size of its skull, jump five times its body length, tread water for up to three days and hold its breath for up to three minutes. They can also gnaw through wires, water pipes and concrete - otherwise their teeth grow about a half an inch in a month. Studies dating from the 70s in the US say that rats are responsible for 20 per cent of all electrical fires.

Rats also smell in stereo, studies say, and so adeptly that scientists have even trained some to detect the scent of explosives in landmines. Unlike dogs trained for the same task, a rat lacks the weight to detonate the mine, which allows the ordnance to be safely defused and the rat to find more than one. Rats have also been trained to detect tuberculosis in human saliva. Scientists can test for the disease in about 20 samples a day, but a rat can test 300. And rats can also detect most of the poisons created to kill them.

A University of Georgia study in March last year found that rats possess metacognition - the awareness of one's own cognitive processes, says a National Geographic documentary Rat Genius, which on Thursday and Saturday also discusses rattus norvegicus' capabilities. But viewers in Hong Kong will miss a cut scene in which a woman is bitten in the nether regions by a rat that allegedly crawled and swam through her lavatory pipes.

Such an incident might change the opinion of rat lovers such as Coco Yu Cheuk-ling, a Hong Kong spokeswoman for People for the Ethical Treatment of Animals (Peta). The symbiosis in humans' relationship with rats is one of the reasons they were made the first animal of the Chinese zodiac, she says.

Peta also calls for more respect for rodents in the Year of the Rat. 'Rats are social animals who become attached to each other, love their families and enjoy playing, wrestling and sleeping curled up together,' it says.

Rats 'feel things just like we humans do', Yu says. 'We [at Peta] don't think it's the right of humans to kill these animals just because they're perceived to be invading our homes.'

Instead, Peta advocates catching rats and relocating them to the wild.

Sze thought the same thing when he met his midnight visitor.

If not to the wild, at least to the nearby Gage Street Market, where the unexpected peanut-butter fan would find friends, Sze says.

So he set a trap assembled from an upturned plastic bucket, a brick and a jar of peanut butter that would be triggered by the movement of a spoon. Well, in theory; the bucket and brick came down, toppled off the counter and broke a tile on the floor, he says. The smart rat had taken the bait, but run away with the peanut butter and the spoon.

'I know next time I click on the light [that] I'm going to see him at the table with a bowl of ice cream,' Sze says. 'Now I understand the desire to build a better mousetrap.'