I loved this book—the anecdotes and the arguments. I thought that it was pretty balanced; with anthropomorphism given quite a lenghty discussion, etc. My favorite passages were the ones about Koko and the other signing gorillas. But this passage in particular caught my eye:

“Zoologist J. Lee Kavanau gave white-footed mice (deer mice) the opportunity to adjust light levels in their cage by pressing a lever. He found that the mice preferred dim light to bright light or darkness, and if left alone would adjust the light level accordingly. But if he turned the lights up high the mice would frequently respond by making the cage completely dark. Conversely, if he made the cage completely dark, the mice would make the light as bright as possible. He also found that if he disturbed sleeping mice, so that they came out of their cage to investigate, they would soon go back inside, but if he put them inside by hand, they would immediately come out, no matter how many times he replaced them. They cared about choice more than comfort.” (p. 121)