Sunny my 4 month old does a great job of using the litter box, but she seems like burying it as far down under the litter as possible. After using the litter box she will cover and cover and dig an dig for a good 10 min until she will finally get out. I do keep the box really clean so it's not a dirty box issue. Anyways, does anyone elses kittens do this and is it a normal kitten thing.