I have three covered litter boxes (out of four) and the cats just "took" to them without any problems. What I did was a couple of days without the lid (i.e. plain old litter box), and then about a week without the door of the litter box. I decided not to use the door portion because the Tanner (my youngest) was attacking Emily (my only female) as she was coming out of the box. It got pretty nasty between them for awhile, but letting her see who was waiting for her solved the problem.

Good luck and you are going to enjoy the covered boxes!!

Cheryl