I always thought that dragonfiles were the big ones and the skinny ones were darning needles. It turns out that darning needles are the same thing as dragonflies. Here's what I learned about them today:
Adult dragonflies have long, thin, needle-like bodies, which is why they're sometimes referred to as devil's darning needles. All species have six legs, two pairs of wings, disproportionately large eyes, short thoraxes and long abdomens that are split into 10 segments. They're generally bright and colorful, although exact colors and patterns vary between species. The largest known dragonfly species has a wingspan of up to 6.3 inches, whereas the smallest has a wingspan of roughly 1.3 inches.
They primarily eat flying insects, such as mosquitoes, aphids, flies, moths, bees and other dragonflies. The type of prey they go for depends on the size of the species. Dragonfly nymphs are fully aquatic and live mostly on insects that live in water. Their modified, hinged lower lips -- known as facial masks -- help them catch their prey.
Dragonflies and damselflies are closely related and may seem at first glance to be like twins. But once you know what to look for, telling the two members of the order Odonata apart is a piece of cake. There are four details that even the most inexperienced bug watcher can use to identify if the insect is a dragonfly or a damselfly. They are the eyes, body shape, wing shape and position of the wings at rest.
Dragonflies have much larger eyes than damselflies, with the eyes taking up most of the head as they wrap around from the side to the front of the face. The eyes of a damselfly are large, but there is always a gap of space between them.
Dragonflies have bulkier bodies than damselflies, with a shorter, thicker appearance. Damselflies have a body made like the narrowest of twigs, whereas dragonflies have a bit of heft.
Both dragonflies and damselflies have two sets of wings, but they have different shapes. Dragonflies have hind wings that broaden at the base, which makes them larger than the front set of wings. Damselflies have wings that are the same size and shape for both sets, and they also taper down as they join the body, becoming quite narrow as they connect.
Finally, you can spot the difference when the insect is at rest. Dragonflies hold their wings out perpendicular to their bodies when resting, like an airplane. Damselflies fold their wings up and hold them together across the top of their backs.
Neither dragonfiles nor damselflies sting or bite. Both are predators of harmful insects, like mosquitos, so enjoy them next time they land on you.