Put some cheese/peanut butter/whatever on the floor. Hide somewhere and when the little bugger goes for the cheese, put a cup over it (or something that just covers it). Shake the bastard around a bit, making him all dizzy. Then take the lid off and BANG with a hammer. Then the little bastard might go home with a SORE head
dont feed the cats for a while, they will start sniffing out whats around.. alternatively, when cats are safely away, put down some ratbait (basically salted meat scraps?) this makes the rats thirsty, so they go seeking water, and hopefully away from your place..