Pest control specialists turned up at the hill at Bukit Batok, next to the Bukit Batok MRT station on Thursday to catch rodents after a video showing a rat colony next to the station had gone viral online.
According to a joint statement released by the Housing and Development Board (HDB), the National Environment Agency (NEA), Agri-Food & Veterinary Authority of Singapore (AVA) and Jurong Town Council, the rat infestation at the hill is a problem created by the feeding of stray dogs.
The resulting food scraps have attracted rodents and encouraged their infestation, the statement said. The infestation had been "kept under control" due to measures such as fencing to keep stray dogs away from common areas, and notices to remind the public not to feed the stray dogs.
The statement also said the issue resurfaced in recent months due to "continuous indiscriminate feeding of the dogs in the area by feeders,".
"We have intensified our pest control measures to eradicate the rodents and in response to public complaints on aggressive stray dogs, we are continuing with stray dog control operations. However, for these efforts to be effective, the feeding of stray dogs needs to cease," the statement added. "Strict enforcement measures will be taken, and we hope the public will understand and support these measures."
Pest control officers were seen anchoring ropes to the side of the hill and climbing up to inspect rat burrows at the top.
"First, we will carry out surveillance and also treat the burrows to eliminate the rats," said Star Pest Control general manager Bernard Chan to local media, adding that the burrows are spread out across the top of the hill across an area half the size of a football field.
Mr Chan added that this could take three to five days to work, or longer depending on whether the rats take the bait. Bait containing rat poison is placed outside the burrows.
Concerns about the use of rat poison have been raised by some, as dogs have been known to accidentally ingest the poison. To this, Mr Chan said: "We have already thought about this before carrying out the procedure. The rat poison is not exposed. We made sure to only put the rodenticide in the burrows, so the poison is underground where all the rats are hiding. The stray dogs will not be able to eat the poison by accident."
The pest control operation is expected to continue over the next few days, he said.
Apart from placing the rat poison, the 22-man team led by him will also be carrying out a "search and destroy mission" by using nets and other rat-catching equipment during the night where the rats usually come out to look for food.
Media reported that about 15 rats have been caught during the operation, but by-standers at the scene say the total population might be in the hundreds.
In the operation to catch the rodents in their nests, a few puppies were believed to have been caught by the pest control specialists and handed over to AVA. Dog feeders were informed of this have been going around to raise funds to have the puppies released.
TOC spoke to a resident who lives near the area, who said that the solution should not be just poisons and traps. "They need to discover where the colonies of rats are and resolve at source."
He noted that the rats have been seeking food outside the slope because of scarcity and have spotted the rats around the walkway behind the NTUC at the station.
He further added that the dogs keep to the hill and do not disturb or harass residents, and any solution to the rat plague should take into consideration the welfare of the dogs.
It is also noted that the food provided by the dog feeders is likely not sufficient to sustain the rat colony of this size.
Animals sent to AVA are usually put to sleep within days, some within just one day, if no one claims ownership of them.