IF people really can't pack thier garbage well you may not have a choice.
Are there areas of the town where you actually see rats openly running around? Or is it 100 siteings throughout the town?
Here's some thoughts..
How do you poision rats without poisioning the rabbits?
When setting bg ol rat traps do you catch the occasional cute chipmunk or bunny?
Why don't people catch thier own rats.. I did when I lived on lovejoy. Some were really big.