Reference: More rats caught in Bukit Batok
Action was only taken after video of the rats running on the small hill beside Bukit Batok MRT was leaked.
When I posted that on my personal Facebook page, a friend messaged me and told me he had alerted the authorities 2 times of the situation. He's not the only person doing that.
It seems that making a video, posting it online is a faster way to get things done. Public shaming the authority seems more effective at getting things done.