Netwinged insects are named for large, delicate, transparent wings with branching patterns of veins. When resting, they make a tent shape with their wings, protecting their long, soft body underneath. A horizontal line divides each of their big, round eyes into upper and lower sections. Netwings tend to have long antennae, sometimes club-shaped on the end. Their petite, but powerful jaws are used to feed on small animals such as aphids or ants. The body plan of a larval netwing is radically different from its parents. Larvae have flattened heads with large jaws that may be long and spiny. Their jaws include tubes, allowing them to suck the contents of prey out after they have stabbed it. Some larval netwings are called "antlions" because they dig sand traps to capture and eat unsuspecting ants. Thanks to their predatory abilities, netwings are used in agriculture to control other insect pests that damage crops.

Insects are by far the most diverse and abundant group of organisms on Earth. More than one million insect species have been identified, and estimates of how many species exist range into the tens of millions. Insects got their start way back, in the Paleozoic (about 500 million years ago) and have evolved in tandem with flowers (coevolution). Insects have become specialized on particular flowers, leading to complex sets of adaptations that couple them in a feeding and pollination relationship (a mutualism). Specialization allows for many types of insects to live in the same habitat, accommodating their exceptional biodiversity. In a backyard in the temperate zone, one might find several thousand species of insects. Specialization can occur within one plant species as well, with different insects using different parts of the plant. In just one species of tropical tree, Dr. Terry Erwin of Smithsonian's National Museum of Natural History found about a thousand species of beetles.