Cinnamon is a great option for killing ants. When an ant inhales cinnamon, it suffocates and dies. Other powdery substances like cayenne or coffee also kills ants through inhalation and suffocation.
One reason to choose cinnamon is because it is not harmful to children and pets. The strong smell of cinnamon disrupts the ants' sense of smell. Ants rely on pheromones to detect food and send messages back to the colony. For cinnamon to be the most effective, ants need to bring traces of cinnamon back to the colony. This causes panic among the other ants and forces the queen to leave the area.