Any member of Odonata, an order of primitive winged insects
found worldwide. Damselflies, in the suborder Zygoptera, have thin bodies
with wings held vertically along the body when at rest. The long, slender,
aquatic nymphs have three, leaflike gills
on the abdomen. Dragonflies, in the suborder Anisoptera, have heavy bodies
woth wings held horizontally when at rest. The stout nymphs have gills at
the anal end. All prey on insects; none attack humans. Length: 18–193
mm (0.7–8 in).