We had a problem, too, and it took months to fix. First thing you have to do is make sure that he is stuck in the attic and can't get out! That way, he will eat the food on your trap. Don't use poison because you don't want a rat crawling down the wall and dying.
Use a rat trap with a piece of walnut. The walnut doesn't crust over like peanut butter, etc. and he will be able to smell it for however long you have it up there. Tie a four or five foot string on the trap because rats like to "flip" around when they get caught and you don't want to try and find a dead rat and a trap in your attic.
Trust me, we've had to catch a lot of rats and this is fool proof!
Use a rat trap with a piece of walnut. The walnut doesn't crust over like peanut butter, etc. and he will be able to smell it for however long you have it up there. Tie a four or five foot string on the trap because rats like to "flip" around when they get caught and you don't want to try and find a dead rat and a trap in your attic.
Trust me, we've had to catch a lot of rats and this is fool proof!