Here's an interesting letter in today's papers about a rat running into someone's home. Now there's a question of jurisdiction - if the rat is IN the house, then it's not the TC's problem. For those worried about TCs cracking down on cats in flats, this is another example of how the TC doesn't really govern what happens within your four walls. That's HDB's jurisdiction.
What I find interesting is that while I agree that the artificial line that TCs draw often seems rather arbitrary, the fact is that the rat is in the house. The people who are going to be most affected are not the TC officers - but the family itself. It's surprising to me that there seems to be almost an abdication of responsibility in this letter - and that the family is waiting for the TC to get rid of the rat for them.
When I am away in the US, there is a serious rat problem in the city where I live. There are rats running around the street as large as cats. I've been told they have killed kittens (and they bite through plastic garbage cans). There is no official to come and fix the problem for you. Almost everyone I asked has a mouse, or rat, problem - they run up the walls of apartment blocks into homes. When we had mice, we just spent a lot of time trying to find the source of the problem (mice will come in as long as there is a tiny hole, especially when it's cold) and blocked up the entry holes. The problem stopped. Interestingly, the problem actually started when a neighbour with a cat moved out above - during the years she lived there, there wasn't a problem at all as the mice never ventured in.
I do however agree with the letter writer that it's best to nip the problem in the bud, and to solve the issue at the root cause. Maybe they ought to encourage community cats in the area and that will help to cut the rat population down.