I was reading this series to my 4-year-old son and he really enjoyed the first couple, but this one taught me that I need to pre-read books even if I think I know the author and her style. The young cat Jane has had a trauma so terrifying that it causes her to become mute except to say "me," and when she's scared, "hate!" My son was (and still is) very tenderhearted and easily worried. I tried to edit as I read, but it was rather difficult. In the end, we had a long talk about what hate is, why rats would be so terrifying, and what it means to be traumatized to the point of being unable to speak. I tried to explain that animals don't hate one another and that there is nothing evil about rats. It was all way over his head, but we managed to get through it. I know that even the first couple books were a little old for him, given the realistic themes of animals attacking one another and leaving their parents so early, but I do think that this book was a departure. It added a psychological dimension that was beyond having to explain that some animals are predators and some are prey. Also, by introducing hate as an animal trait, I felt like it was a forcing an anthropomorphism that didn't fit with the other books.