Nectar is a sugar-rich liquid produced by plants. It is produced in glands called nectaries, either within the flowers in which it attracts pollinating animals, or by extrafloral nectaries which provide a nutrient source to animal mutualists, which in turn provide anti-herbivore protection. Common nectar-consuming pollinators include bees, butterflies and moths, hummingbirds and bats.
Nectar is an ecologically important item, the sugar source for honey. It is also useful in agriculture and horticulture because the adult stages of some predatory insects feed on nectar such as almost all solitary wasps. In turn, these wasps then hunt agricultural pest insects as food for their young. For example, thread-waisted wasps (genus Ammophila) are known for hunting caterpillars that are destructive to crops.
Nectar secretion increases as the flower is visited by pollinators. After pollination, the nectar is frequently reabsorbed into the plant.