Swarms of mating crane fly males dance above vegetation waiting to seize females. Around the pond where I took these pictures, there are thousands of these flies - they look like huge mosquitoes on steroids, but they cannot sting or bite. They are very clumsy fliers, their legs being twice as long as their bodies. One would think them willing photographic subjects, but they are very alert and do not sit still for very long unless caught "in the act."
Habitat: Humid areas near ponds, streams, marshes. Range: Worldwide. Food: Adults do not feed.
Larvae feed on decaying vegetation, fungi and roots.
Life Cycle: Slender eggs are laid on moist soil or mud near open water. Fully grown larvae pupate overwinter in the soil, emerge in spring.

The small, bulbous structures are called halteres. They are used for balance and vibration damping during flight. All true flies have these organs; they evolved from the (absent in flies) second set of wings present in many other insects.