Horton Hears a Who! (1970)

In this story, Horton discovers there is a microscopic community of intelligent beings called the Whos living on a plant that only he can hear. Recognizing the dangers they face, he resolves to keep them safe. However, the other animals around him think Horton has gone crazy thinking that there are such beings. They resolve to take action for his own good, and Horton and the Whos must struggle against these impossible odds to prevent a tragedy.