Ever have rats suddenly show up in your building? I have. That's when you speed dial the city to fix their problem.
Solid Snakes, maybe? Or Lions?
Ms yellowkitty will develop quick the sense to keep away from its path, or show their nails, or climb a tree.
Btw, how did you "catch" them? Were they Norwegian rats?
It's considered more humane and safe than poison. Some cities use this method.