In this quote why does Frederick Douglass use the words "trough" and "pigs"? “It was put into a large wooden tray or trough, and set down upon the ground. The children were then called, like so many pigs, and like so many pigs they would come and devour the mush; some with oyster-shells, others with pieces of shingle, some with naked hands, and none with spoons. He that ate fastest got most; he that was strongest secured the best place; and few left the trough satisfied” - excerpt from Life of an American Slave, by Frederick Douglass, 1845