for my cats, they do share the litterboxes. i have 8 cats, four big cats (almost a year old), one kitten (about 2 months old) and three one month olds.

but of course, now only five sharing the three litterboxes, one big and two mediums. i'm planning to add some more for the babies.

if you are rajin enough, the cats can share... i do the cleanup once a day, depending on the usage of the boxes. some of my cats do their thing on the toilet floor