Around 4,000 plant species from different parts of the world secrete nectar outside their flowers, such as on their stems or leaves, through secretory glands known as extrafloral nectaries. Unlike floral nectar, extrafloral nectar does not attract pollinators; rather, it attracts insects that defend plants, such as ants. These insects feed on the sweet liquid and, in return, protect the plant from herbivores. However, this protection comes at a cost.