All my boxes have hoods. When I have a kitten in the house, I have always taken the cover off on and prayed the kitten would use that one; dumb, for sure! I know some of the other cats use the uncovered one, and of course it is the cats who "dig to China," leaving a pile on the floor. Honestly, I no longer remember WHY I do it for kittens. I know kittens under a certain age should not have clumping litter, only clay. I think it is under 3 months.