After more than 300 hours of monitoring for rat movement, 20 infrared cameras deployed to track them at night and the clearing of vegetation, the Bukit Batok rat problem seems to have been solved - at least for now.
Over 230 rats were killed in a hilly area near the Bukit Batok MRT station in Bukit Batok Central, and residents say the days of rat horror are over.
The National Environment Agency (NEA) said there has not been any feedback on rats at the vacant plot of land - about the size of a football field - since it was declared rat-free in January.
The Housing Board (HDB) started clearing the vegetation on the hill after the completion of rodent eradication. It did not reveal the cost of eradicating the rats.
"We are clearing the undergrowth in the forested area, as well as a few trees which are in danger of falling, so as to better maintain the land," said an HDB spokesman. "Keeping the land well-kept will minimise the recurrence of rodent infestation and facilitate the removal of hiding ground for stray dogs."
During the operation, pest controllers found about 10kg of food left for stray dogs in the area, which was said to have contributed to the rat woes.
The HDB is currently re-turfing parts of the hill. "Newly-planted vegetation will need time to grow," said the spokesman.
The Straits Times understands that the undergrowth was cleared manually. The re-turfing of grass will be completed in a few weeks. Surveillance cameras have been put near the fencing on the hill to monitor those who feed stray dogs indiscriminately.
The rat problem first came to light last December after Bukit Batok resident Ryan Keith Smith took videos and pictures of the rodents and posted them online.
Pest controllers spent the first part of the extermination process attacking the rats' nests and burrows. It involved about 30 pest controllers, who scoured the area and used infrared cameras and binoculars to track rodent activity.
Star Pest Control general manager Bernard Chan, who led the exercise, told The Straits Times the clearing of thick vegetation will make it easier to spot rats if they are still around.
Pest controllers are still monitoring the area once or twice a week for rodent activity, he added. They look out for tell-tale signs such as rat droppings, food waste and rodent nests.
"We have not detected any (rat) movement at the moment, which is a healthy sign," he said. "It's unlikely that they will return unless there's food available."
An NEA spokesman said it has stepped up inspections of the 13 NEA-licensed food shops near the area and found no infestation there.
"All the food shops have engaged licensed pest-control contractors and have also increased the frequency of the pest-control measures," the spokesman said.
"NEA has also reminded all the food handlers and food shop operators to practise proper refuse management and to properly store their food and raw ingredients at all times." These measures would help ensure no food is lying around to lure the rats back.
Residents have noted an overall improvement. They have also noticed fewer stray dogs now.
The Society for the Prevention of Cruelty to Animals said it received several dogs from the area from the Agri-Food and Veterinary Authority. They have been rehomed, said SPCA executive director Corinne Fong. It is not aware if the other stray dogs have moved elsewhere.
With the rats gone from the hill, residents are hoping it can become a place for all to enjoy. Said Madam Vimala Devi, 51, who is self-employed: "It would be good if something can be built, such as a jogging track."
Additional reporting by Andrea Ng