There are about 5000 species of dragonflies and damselflies. The oldest dragonfly fossils are from 325 million, damselfly fossils from 250 million, years ago. They eat other insects, including many mosquitoes, often in groups especially when their prey is swarming. Dragonfly eyes cover most of the head. Each compound eye has 28,000 individual lenses. Analyzing visual information occupies more than 80% of their brain. Damselfly eyes are similar but further apart and smaller. Both are also predators as fresh water nymphs, which lasts a few weeks to several years, depending on species, before emerging as flying terrestrial creatures for a few days or weeks. They present a wide range of beautiful colors and patterns.