"Ascalaphus sinister" Owlflies are dragonfly-like insects with large bulging eyes and long knobbed antennae. They are neuropterans in the family Ascalaphidae; they are only distantly related to the true flies, and even more distant from the dragonflies and damselflies. They are diurnal or crepuscular predators of other flying insects, and are typically 5 cm (2.0 in) long. The Ascalaphinae are the namesake subfamily of the owlfly family (Ascalaphidae), winged insects of the order Neuroptera. Most are found in the tropics. Their characteristic apomorphy is the ridge which divides each of their huge compound eyes; they are thus known as split-eyed owlflies.