I have three 5 1/2 week old kittens who were born to a young feral cat on my front porch. They've all been to the vet already to get an upper respiratory infection cleared up, and are otherwise healthy. They're doing great and their mama cat is happy to come in to feed them regularly (yes, we've spoken to our vet about sedating her here and getting her in to be spayed). The mother, being a feral cat (or we suspect may have been lost or ran off at a very young age), does not use the litter box, so I'm trying to train these kittens myself. I've tried putting poop in the box, scratching the litter, moving their paws to scratch the litter, putting them in the box at various intervals after mealtime, but they're not taking to it. I've switched from clay non-clumping to a non-clumping pine litter (also trying to get mama cat interested), and now they like to play in the box, but continue to go on the sheets I have lining the room. Any suggestions would be greatly appreciated!