Emmy and the Incredible Shrinking Rat

Emmy was a good girl-too good, perhaps. The rat, whose cage sat on the counter next to Emmy's desk, was not so good. On the other hand, he was the only one in Emmy's class who would talk to her. The rest of the kids barely knew she existed. Even her teacher didn't seem to know she was there! Only her nanny, the lovely-but-sinister Miss Barmy, really pays her much attention. And Emmy would rather she didn't....

Why does the rat talk to Emmy and no one else? Why do Emmy's schoolmates hardly no...