Short-lived insects are typically those that have a lifespan of only a few days or weeks. Two examples of short-lived insects are mayflies and dayflies. Mayflies, also known as ephemeroptera, are aquatic insects that live for only a few hours to a few days in their adult form. Dayflies, also known as ephemerids, are terrestrial insects that live for only one day in their adult form. Both mayflies and dayflies have a short lifespan due to their lack of mouthparts, which prevents them from eating and surviving for longer periods of time.