Kitten = 4 months old. Closet = approx. 4' x 3'. Please allow me to explain.
Shortly after Gadget arrived at our house she hurt her foot. We were instructed (by vet) to keep her quiet, and not allow her to jump on anything. Hard to do that with a kitten, so we made a nursery in the closet for her, for when we were unable to supervise her. We have been shutting her in every night since (leg is healed). ***Edit* ONLY AT NIGHT. Gadget does not live inside the closet. She is there while we sleep only. SIX hours a night typically.***
Why not give her free range, you ask? Well, we've tried that and she torments us and our older cat, who truly values his nightly snuggle time with mom & dad.
We could just shut her out of the bedroom, but then she cries at the door for a good half-hour. She cries in the closet also, but it's harder to hear her, so we can still sleep :r . Also, the older cat doesn't really appreciate being locked in the bedroom all night--sometimes he likes to wander around.
If we had a spare bedroom we would put her there, but we don't (apartment). The closet has a window with a sill that she can sit on to look out. Both cats hang out in the closet sometimes, of their own free will. We of course leave her plenty of toys. Still, I realize that it's a small space and it seems a little mean to me. The closet already has two very secure shelves high on the wall-- I am thinking that we could install some cat shelves, throw in a scratching post and perhaps it would be quite comfortable. What do you think?
Here's proof that they really do hang out in there of their own free will (hardly glamorous, but they ARE cats):