What's the difference between a buffalo and a bison?

The joke “What’s the difference between a buffalo and a bison? Can’t wash your hands in a buffalo!” is a play on words that exploits the phonetic similarities between terms and the unexpected shift in context. Initially, the setup invites listeners to consider the biological differences between two large mammals: the buffalo and the bison. However, the punchline humorously subverts this expectation. “Bison” sounds phonetically similar to “basin,” a term for a bowl-shaped vessel, often used for washing hands. The humor arises from the unexpected comparison, contrasting the anticipated zoological answer with the whimsical idea of washing one’s hands.