This is not a problem per se, but just something I thought I'd share to
perhaps get some insight.

Up until November of last year I had two cats. My 19 year old, Murphy,
passed away right before Thanksgiving. He lived with me from kittenhood,
so we literally shared 19 years together. (Longer than my own dad was in
my life.) Anyway, 4 and a half years ago I also adopted a female kitten
(named Sassy) who is now my only cat. I noticed, over the years, an odd
behavior that she developed. She seemed to have an objection to using a
fresh litter box. I wondered, at first, if it was the litter she
objected to, but I never changed it and it was the only one I ever used:
Feline Pine or versions of that type.

When Murphy was alive, Sassy would seem to wait for Murphy to use the
box and only then would she use it. If that didn't happen, she would
literally pee or defecate in the tub or on a throw rub, which drove me
insane. Fortunately, Murphy often jumped right in the box as he was
always drinking due to his kidney deterioration. Anyway, now that Murphy
is no longer here, it's up to her to "christen" the litter box. The
other day, after I thoroughly cleaned it, replacing all the litter, I
noticed that she didn't use it all day. Nor did she use it the next
morning. So, since I live in an apt. and she is an indoor cat, I began
to look around to see if she was going somewhere else, but could find
nothing. I was really getting worried about her as she WAS eating and
drinking. Finally, I took some of the soiled litter, which I still had
in a bag ready to be put out with the trash, and threw a few scoops in
the clean box. Within the hour, she was in the box, using it.

Now, I know.

Unless I get another cat who will use the box first, I'm going to have
to keep throwing a few scoops of her soiled litter on the fresh to get
Sassy to use that box. Otherwise, I think she'll explode.

What do you make of this if anything?

Sandy
P.S. Maybe the litter is still the problem. Maybe she doesn't like those
pellets that break down into sawdust once used, but she DOES prefer the
sawdust??? One's hard'; one's soft. Maybe the pellets hurt her feet???