Among some animals, smell plays a different role from its role among people. Ants use smell to mark a path to food. Female butterflies attract male butterflies with a smell. And worker bees respond to the smell of the queen bee. Scientists have studied how people respond to smells too. How does the smell of a person affect others? By studying this important question, scientists have learned a lot about human beings For example, they have uncovered one of the reasons that two people fall in love: They smell good to each other!