pest control is best , we had pigeons and the pest man fed them pelltes that made them high and fly away and eventaully die somehwere else , pmsl my cat ate some and was off her face for about a day . the pest man will know whats the best way to get rid of them , as they are a pest and qld is better off with out rats , i know its hard to "need" to kill /get rid of them but unless they are a domestic pet then the bad points about wild ferral rats out weight the good .

give some ppl a call and ask how they get rid of rats and pick the one thats not so harsh , most chemicals they use these days are family friendly too