I've had several cats over the years...taken in both young and old. I always just took them and put them in the litter box and that's all it ever took. I had only one who ever used the floor and that was my husband's fault. He closed the cat up in a room and didn't realize it all night long. Next day we heard him crying and went to get him and he had messed in a corner, but I probably would've done the same thing. He headed for his water and food like a bullet. And always used the litter box after that.

We had two outdoor cats. When one gog attacked by dogs, we decided the one left would become an indoor cat. The first time she used the bathroom, it ws in my sons closet. We scooped it up and put it in the litterbox. After that, she always uses the litterbox.

I have always heard that you need one more litter box than cats---Toby has 2

Having hand raised a couple of kittens that just had their eyes open, I took a small box and cut the sides down and placed it and the kittens in a larger box at night with an area for sleep and at the far end the "litter box". I placed a drop of ammonia in it as I have always done to train kittens or cats. They both adapted to that and after growing some to where they could get in a regular litter box I never had a problem. Worked for us, hope you find something that works for you.

It still won't keep him from spraying (marking his territory). Even females spray. I've had cats and won't again. They get up on counters. I don't hate cats, I just don't want cats. I won't eat where some one has cats. Every time in the past, I've had cat fur in my food even after counters have been washed off. I love my dogs but when they're gone I'm done with pets. I Swiffer my home twice a day even after brushing my dogs and I do that outside. Good Luck with your cats.

Most cat experts recommend one cat pan for each cat plus one more. Also recommend don't place cat pans next to each other and not by their food or water. A protected place is also good. Have you taken kittens to vet? They might have health issues.
Just read all the posts. Sorry to repeat what everyone else said.

I agree with the suggestion that several have made about providing an extra litter box. Sometimes they have very strong feelings about sharing, or there may be a signal from the earlier cats that the new one isn't welcome in their bathroom territory. Sometimes it has to do with one or more of them having intestinal parasites, and the vet will be checking for that. You could ask the person you got him from what brand and "flavor" of litter she used, because sometimes they're just picky if it doesn't smell exactly like what they're used to. If you don't like her choice, you can start with it and gradually mix in your preferred one.

Try hydrogen peroxide for cleaning the areas where he's gone (test first in a hidden spot because it might bleach!). Once they have marked a spot with their aroma it's very hard to break them of the idea that it's a good place to go.

The two cats I had until a few months ago didn't mind sharing the litter pan, but I learned after one cat died that they each used only one area of the box. It was weeks before Pogo would go in the back of the box that used to be Bee's area, and she still usually does not go there. Years ago when we introduced a third cat, one of the two earlier cats resented sharing the litter with him and was going in a corner behind the water heater, which was a very hard area for us to reach! We put a new litter pan near there and she straightened out her act.

You could ask the vet about using calming collars or pheromone mists which are supposed to help cats get over anxieties.

Good luck with your new fur baby!

It's said you need an extra box---so try a 2nd one of they're both using the same one. . Also, I have a one (11 years old) who WILL NOT pee in clumping litter...so with the 2nd box, a different litter.(BTW--I have 3 cats and 3 boxes)

So sorry you feel that way---cats are SOOO loving. We have a saying in our home...."Pet hair is a condiment in our house" as..No outfit is complete without pet hair.

Cats have a very keen sense of smell. Maybe the kitten doesn't like the smell of the litter. My cat didn't like the litters that claim to be odor fighters, I don't blame him, even I thought they smelled like soap. Try using plain old, unscented litter and see if that helps. When I switched litters it solved the problem. We buy the unscented litter at Petco, you can buy the tub of litter and take it back for refills at a reduced price. They have a big sandbox like structure in their stores and you just refill the container.