We'd like to make a Who's on First? joke, but we're not sure we can make it land. Plus, those Whos are just too cute to poke fun at.
Anyway, let's start with a "Do The Whos Exist?" rundown:
Bottom line: yes, they exist. The animals are just a little paranoid.
Even though the Whos are awfully small, they don't let their small-ness hold them back. After all, the mantra of the book is "A person's a person, no matter how small!" These guys are able to build an entire community with clocks and bells and whistles galore. And what's more important, they band together to cause a ruckus that can be heard even by the small-eared monkeys and kangaroos.
Like Horton, the Whos won't give up even when the odds are stacked against them.
If we read the story allegorically, the Whos might represent the Japanese-American population during World War II internment. These folks are just trying to live their own lives, but they've got other people trying to upend everything and destroy them because they fear their "otherness."