The rats are going to crawl to where ever they will/can until they drop. Doesn't matter where you leave the bait. Best is to put it in the ceiling, and their nest, so there is no chance of the bait being taken out into reach of pets, and they die out of reach of being eaten too by pets.
My mum lives in inner Sydney. If only she could get to have her neighbours admitt to there being a problem!
would make things soooo much easier.