Monsters, Inc.'s main duty is to provide all citizens in Monstropolis with energy in the form of captured screams collected from children. They accomplish this by crossing into the Human World through the closets of children's bedrooms and scaring them to the best of their ability. The screams are then collected in special canisters for use as energy. The amount of capture screams collected is a performance metric and is displayed on the company's leaderboard.