Killing more than rodents

A Facebook reader has expressed concern to Sahabat Alam Malaysia (SAM) regarding the extensive use of rat poison in drains in the Little India area in Georgetown, Penang. It is indeed worrisome as the open drain system leads directly into the sea and after every heavy downpour the poison gets washed away and diluted in the sea.

Rats are a human made problem and their populations are on the rise with towns and cities struggling to keep up with rat infestations. In urban and suburban areas, the biggest users of rodenticides are regular consumers who buy the products at hardware stores for home use or hire pest-control professionals to treat their property. In agricultural areas, it is applied by farmers to keep rodents away from crops.

Rats like to live where people live adjusting quickly to the neighbourhood. They prefer to feed in and around homes, restaurants and business premises. Upon entering a neighbourhood with easy access to food, they will thrive. They will also settle for scraps from trash bags and cans, wet markets, gardens and yards, and what they can find at the community refuse disposal center.

Tolerating rats is not something many people want to do; for this reason, people and rats are unlikely to coexist peacefully. That we do not tolerate their presence does not mean that we should resort to cruel methods of controlling rat populations. Generally, poisons are used, or trapping is employed to reduce the population, only to leave unaddressed the cause of the problem in the first place – dirty habits of Malaysians in discarding food waste and garbage indiscriminately.

Many people who set bait traps do not realise the poisons work their way up the food chain. Most rat poison kills more than rats; it also poses a fatal threat to birds of prey and other wildlife.  If the birds do not die, the rat poison would have a negative effect on breeding and its state of health. Sadly there have been no comprehensive study or review into our wildlife affected by rat poison in Malaysia.

The natural way of rodent control is large birds of prey such as hawks, falcons, and owls.  Owls are particularly formidable predators, as their nocturnal behavior ensures that they are most active when rats go out in search of food.  The more common mouse predators are our domesticated felines and dogs that are likely to pursue and attack rodents when discovered inside homes.

On the other hand,  rice field rats causes significant losses both in the field and in post harvest rice management. They are very sensitive to human disturbance and are rarely found in homes. Their natural predators are the wild cats, birds and snakes.  They do a good job in controlling the rice field rats and should not be  eliminated from the paddy fields.

Killing the natural predators of rats and mice will only worsen the rodent population.

Rather than looking for more powerful and potentially dangerous ways to kill rats, the only real answer to people’s conflicts with these animals is to find evidence and hotspots of rodent infestation or conditions likely to attract them, and to address the source of the problems rather than pouring more poison in our urban drains.

This includes measures such as keeping our home and property clean, reducing food waste, composting food scraps promptly, ensuring rubbish bins at food outlets have tight-fitting lids and are regularly emptied, determine potential rodent entrances and block them where possible, remove unwanted undergrowth, etc to address the cause of infestation.


Letter to Editor, 2 December 2019