There's bad news for city dwellers. Rats are on the move. These rats are being caught in suburban streets. The introduced, Black and Norwegian rats, travel through storm water drains and sewers, getting into your roof, where they pee and poo, increasing the chance of spreading disease.

"The diseases we are talking is a full range from the parasites, the round worm that occur in the lungs for example, that transfer to humans through to the viruses."

Only one virus, known to spread from rats to humans, has been found in Australia, the LCMV, but so far, it's only been found in mice. But, according to CSIRO's Dr. Grant Singleton, this doesn't mean that other viruses are not here. And there are a number of rodent borne bacterial diseases that have caused health problems in Australia.

In parts of Asia, the locals face an added problem. There, the rats destroy their major food source and livelihood, rice.

Dr. Singleton's team has been working with the local farmers to find new ways of dealing with the rats, many of which are different to those found in Australia. One method where plastic sheeting is wrapped around a field, trapped up to 20 thousand rats over two months.

"In Indonesia annually they lead to seventeen per cent loss in crop production. And if you work out how much rice that is, if we were able to control those rats then there would be enough rice to feed 25 million people."

Controlling rat populations will help prevent the threat of disease in Australia, but in Asia could mean the difference between survival and devastation for local communities.

Long Version of A Rat's Tale

Dr. Grant Singleton
CSIRO Sustainable Ecosystems
P.O. Box 284
Canberra ACT 2601

grant.singleton@csiro.au