His poem, To a Louse, is a commentary much like George Bernard Shaw's opinion of how dogs relate equally to people, regardless of station in life.
Shaw pointed out that in the manor house, if the lowest staff member formed a friendship with the dog, the pet would greet the servant as happily as he greeted the owner of the home.
To a Louse tells about the creature crawling on a cultured lady's hat, and hints that it doesn't realize it should be on a woman with less affluence.
Burns' observation of the ordinary things in his world gave his writings insight, making the words worth reading two centuries later.