Both of these series are considered Young Adult books. Like around Jr High age. The Warrior books are well written, I find them a little disturbing because the violence in these kitties' clan world closely resembles the violence in our own society. There are some deaths I found disturbing because in nature I just don't see it happening, but I do think the books are very good at depicting how society as a whole, is today.
Rather brutal, but kind, generous and loving, too.
The Warriors are fairly new on the book scene and growing in popularity. It will never reach Harry Potter status, but the kids at the library enjoy the books and keep them steadily checked out.
The Ratha series, I understand began in the early 80's and has been re-printed/released to revive with her newest publications of the series. Author is Clare Bell.