"Rat killer" is a funny headline but I hope (though I'm not that confident) that this person will not focus on directly killing rats. To state the obvious, for

"Rat killer" is a funny headline but I hope (though I'm not that confident) that this person will not focus on directly killing rats. To state the obvious, for that to work you have to kill rats as fast as they reproduce (which is fast) and the second you stop the situation goes right back to where it was. To take a cue from what seems to work with pigeons, they need to provide less rat food and/or limit reproduction. The second one is easier with pigeons (you can build roosts for them, then replace the eggs with fake ones - this is really done).