To kill a mocking bird

I was called in to take the lunch-hours at the restaurant today. We wiped, scrubed and cleaned and stood ready to take on the lunch-eaters. To our surprice, at 11.30 a bird stood on our floors. Black with a bright yellow beak, he sang his song and walked across our floorboards.

Suddenly, his little walk had led him up on the tubes and pipes in our ceiling. He sat there above our counter while we studied him for a while. ..and then.. he took a shit in our milk.