Rat Behavior and Extermination is a book found in Dishonored.
Used to be, you'd go out with a bag, a stick with a nail on the end, and catch as many rats as you could in a night. The City Watch paid by weight. My husband Benjamin and I mostly worked alone, and we got by. If we found a place where the rats were real bad, sometimes we'd hire a crew of street brats to work with us, the younger ones who didn't make trouble. We'd pay them with bread and apple cider.
Once the plague came, the rats were different. Meaner, bigger, and a little quicker. You had to watch yourself. If you got cornered, they'd turn and the swarm would come back at you. I barely got away with my skin a few times, down in the sewers. The bites hurt afterward, but it was the sounds they made that stayed in your dreams at night.
It got more dangerous, and the City Watch started paying better. But that didn't last long because after a while too many people had been stripped clean, trying to fill up a bag. One slip and they'd be all over you, gnawing and trying to chew down to the bone. That's how I lost my poor Benji.