10 little-known facts about sewer rats

A common black rat. -- PHOTO: WIKIMEDIA COMMONS
A common black rat. -- PHOTO: WIKIMEDIA COMMONS

SINGAPORE- Rats have been all the rage since a video of them scurrying up and down a grassy slope near Bukit Batok MRT station went viral.

The rat situation in that area gained attention after a resident in the area took the video, and posted it on Facebook. Mr Ryan Keith Smith, 33, also alerted the authorities to the problem. Pest busters have been sent in to catch the rodents which belong to a species known as Norway rats, or sewer rats.

Here are some little-known facts about these pesky creatures.

1) They survived atomic bombs

Sewer rats survived atomic bomb tests in the 1940s conducted on Eniwetok Atoll in the Pacific Ocean. Most of the animal and plant life on the coral atoll of 40 islands were destroyed, except for a large colony of rats. The soil was highly radioactive following the atomic tests.

Scientists also found that the rats could develop resistance to warfarin, a kind of rat poison used in the 1950s. Poison-resistant rodents began to appear in the 1960s and some were eating warfarin as food.

2) Where there is a hole, there is a way

Their burrows are usually about five metres deep and about a metre wide. Sewer rats can damage the foundation of buildings by digging these burrows, which contain their nests and escape routes.

3 They have routine meal times

They have their breakfast after sunset, and their supper, or dinner, just before sunrise. If they are seen in the day, it could be because there is high competition for food, and the younger or weaker rats need a headstart.

4) They don't need a "Danger! Keep out" sign

Sewer rats can sense danger. If they do, they will try to escape, lie low and return when it is safe.

5) It's a rats eat rats world

If there is scarcity of food, they may practise their own population control by eating young or weaker rats.

6) They are possessive

They mark their territory the same way dogs do, by urinating.

7) They can't actually eat a lot at one go

The amount of food they eat is usually 10 per cent of their body weight. They hoard the rest of the food in their underground burrows.

8) They follow a strong hierarchy system

It is usually the younger, weaker rats that had to leave the nests to forage for food.

9) They love home sweet home

Rats have been known to turn aggressive when their territory is invaded. They may attack dogs, cats, and even people.

10) There are few things rats can't get their teeth in

Rats, whose teeth grow 13cm every year, can gnaw through plastic water pipes, irrigation systems and garbage cans, wood boxes, dry wall, and even cinder block.

Source: www.terrierman.com. www.askdrlouise.com