My 5 month old kitten rarely uses the litter box

Instead she uses the carpet in the washroom. She then scrapes the carpet as if it was the litter? She has three other cats living with her the same age, and they have no problem using the litter box.

There are also four litter boxes in my house. Any ideas?

My thoughts: I'm sorry to hear your kitten is having problems. If she didn't always do this, she may have developed a medical problem that's causing her not to use the box.

Is it possible she's having a conflict with one or more of the other cats? If one cat is box guarding, that could cause her to find some place else to do her business.

Keep in mind that cat behavior is often driven by scent. She may return to the same spot over and over again until those scents are gone and she finds a better option.

You can try blocking access or placing a litter box right on the spot she's using. Then, slowly move that box each day to a new location.

If that doesn't work, and your vet verifies there's no medical issue, you can try isolation retraining.

I hope that helps and please let us know how she comes along.
-Kurt