Animal Jokes
Question & answer
Why do cows wear bells?
Because their horns don't work.
Behind the Groan
Horns That Never Honk
Cows have anatomical horns, but a vehicle horn is expected to make noise. The joke pretends cowbells are replacement warning devices for broken horns. Ask the setup as if there must be a practical farming reason. Emphasize “work” only slightly; the plain delivery keeps both meanings of “horns” available until the answer lands.