My cat (a 2 year old female Bengal) has a few issues related to the litter box; one of the strangest is that she can't seem to figure out how to properly bury her poop. She'll go to the litter box, do her business, and then scratch at the plastic sides of the box rather than the litter. Usually she'll bend down to give her poop a sniff, and then give the wall of the litter box another try before leaping out of the box.
Her brother sometimes comes by and buries the poop for her when he does his own business, but in the meantime it stinks to high heaven. She's clearly operating on some kind of instinct (while(poop_smell == true & tries < 2) {dig(); tries += 1}; leave()). Is there some way I can teach her that she needs to dig at the litter in order to make the poop smell go away?
UPDATE: As several answers suggested, I got a larger litter box. It's a huge 1.5" x 2.5" plastic storage tub. And yet... She still scratches at the side of the tub instead of the litter to bury. Previous owner tried to train them to use a human toilet for a while when they were kittens, and maybe they got the thought in their head that they had to scratch at something hard like porcelain?