Ants in the Pantry (1936)

The Stooges are pest exterminators who drum up business by planting vermin in a ritzy mansion where a party is going on. They are hired, but must pose as guests to work unobserved. They ruin a piano and generally make a mess of the party, but the hostess passes them off as vaudeville comedians and they are invited to join the guests on a fox hunt.