Need help with litter box: kittens vs. adult cats

Someone please help me!! I am at my wits end and cleaning the bathroom where our 7 week old kittens are living at least twice a day, if not more. Its not the kittens that are the problem! Its the mother cats (and sometimes the dad), who insist on using the tiny litter box I have set out for the kittens. The kittens are using the box great and it would be fine if it were only them! I tried placing the box underneath a chair with a bar thinking that would be an obstacle for the big cats. Nope, they still found a way to stick their butts in there and use it. Then I got a tiny box that the older cats can barely fit into and they still want to use it. I keep their own large litter box scooped out and until this nex box showed up there was never a problem with accidents. Does anyone know of a special litter box for small kittens that the older cats could not get inside? I'm thinking of rigging something over the box myself but I'm not that handy.

What do breeders do when they have litters of kittens? Does everyone always use the same box?

Thanks in advance!

i had the same problem the mum would always use the same litter box as her kittens and not the big one, i just cleaned it every time she used it which helped, other then that i wouldnt know what to suggest.

LOL! I had the same thing happen...these big cats trying to fit there tush in this tiny litter box..it was so funny...I just cleaned it out. There is really nothing else u can do.

I have a covered litter box

maybe you can try that - maybe the cats will be too big to fit throught the "door"

Most breeders have a very large cage that the kittens stay in while litter training. Only mom is in there with the kittens - no other adults. And my queens usually would use the normal size pans and maybe once or twice the smaller one.

You might try a little larger (taller) pan and put it next to the shallow one - if the kittens start climbing in and out of the bigger pan with not too many problems, then you can eliminate the shallow pan.

IMO if you have the kittens in the bathroom, how are the other adults having access if the door is closed? Or are they waiting there to come in and then go right for the pan?