Females lay fertilized eggs in the ground. Larvae can be found in forests near rotting and dead wood. It eats other bugs and grubs that it finds in the dirt, including June Bug larvae. Because of their predatory diet, this type of fly is considered beneficial, removing threats to gardens before they can develop. Eventually, Mydas fly larvae pupate in small chambers they create in the soil and emerge as flying adults.
Adults are seen in virtually everywhere (parks, garden, meadows, open lots, forests, etc.). They feed on other insects and caterpillars, including flies of other species, but they may just drink nectar. They are very good fliers, though it may not appear to be the case at first glance. They tend to look a bit clumsy in flight. They are most active in the summer months.