Title. I have a rat problem and all sources recommend the poison Brodifacoum to kill animals like this. I made a batch of food, crushed an entire package in it and they ate ALL of it, I mean, if it doesn't kill them then they are immune to it. It says a lethal dosage is 25 kg of it, the box had 45 GRAMS, I mean, that's like 40,000 times the lethal dosage. (if my quick math is right)

Any idea how long it takes for the stuff to work?

http://en.wikipedia.org/wiki/Brodifacoum