The kittens (6 weeks old tomorrow!) started pooping randomly on my carpet, so I moved them into the bathroom. They pooped behind the toilet mostly for the first few days, but then I laid down newspaper behind the toilet where they were excreting. Now they don't seem to be pooping anywhere. The only place I can imagine them going is underneath the cabinet. I haven't seen them go in or come out of the cabinet as I have when they've done it in the kitchen. How can I train them to use the newspaper-lined tray I've set out for them as their litter pan instead of as a bed?!? They have a bed that they all use and love, but still occasionally use what I want them to poop on as a little bed, too...