There's a rat in the bin!

I know many people have cats that hunt. I am sure many of them collect rats, and much as I love pet rats, I'd rather not have the wild ones too close to my house, sorry. So this morning when I walked into the bathroom and found one, dead, I wasn't entirely surprised. I did clear it up though. Distressingly the bathroom still smells of dead rat tonight. I had been pondering what to do about it when Tet came home. I mentioned this to him. "Yes", he says "it would". "The rat is still in the bin". I had told him this morning about the rat. The thing is I didn't put it in the bathroom bin, it would smell. It seems however the cats would. It's nice that they disposed of their trophy so neatly, but how do I train them to put it in the kitchen bin, or better yet outside?