Spring finally arrives (la!) and Horton's so-called "friends" (76) discover what he's up to.
(By the way, Horton doesn't appear to have any elephant friends. We see a giraffe, a hippo with a squirrel on its back, a kangaroo with a joey in her pouch, and in true Seussian form, various animals we can't clearly identify.)
Horton's position just makes their day. They're total bullies, and they can't stop laughing and teasing him.
The peanut gallery runs off down the hill, dying of laughter.
Playing would sure be nice, poor isolated Horton admits to himself.
But he keeps on sitting, motivated only by his complete loyalty to the egg.