[9][10] Females oviposit in aquatic vegetation, eggs laid beneath the water surface.

Nymphs (naiads) are aquatic carnivores, feeding on insects, tadpoles, and small fish.

Adult darners catch insects on the wing, including ant alates, moths, mosquitoes, and flies.

Vagrant individuals have been seen far outside of their normal range including sightings in Alaska, Russia, China, Japan, France, the United Kingdom, India, and Bermuda.

Adults primarily prey on winged insects, including wasps, flies, butterflies, and other Odonates.

Adults are preyed upon by birds and occasionally robber flies, spiders, and other large dragonflies.

[9] There are several species of migratory dragonflies in North America, but common green darners are the best studied.

Recent research has indicated that the annual life cycle of Anax junius is likely composed of at least three different generations.