8 Things You Never Knew About Dragonflies

Dragonflies were one of the first insects to inhabit this planet, arriving on the scene around 300 million years ago. They've had many millennia to perfect the art of hunting, flying, and living an extraordinary amount of time (for a bug anyway). They've even developed a knack for flying backward, which comes in handy when trying to catch flies and mosquitoes.

Here are eight facts that may change the way you look at these unique, ancient, and incredibly varied insects.

1. Dragonflies Can Intercept Prey Midair

Dragonflies are flat-out terrifying if you're a gnat, mosquito, or other small bug. They don't simply chase down their prey; they snag them from the air with calculated aerial ambushes. Dragonflies can judge the speed and trajectory of a prey target and adjust their flight to intercept prey. They're so skilled they have up to a 97% success rate when hunting.

2. They Have Incredibly Sharp Mandibles

Dragonflies and damselflies belong to the order Odonata, meaning "toothed ones," a nod to their serrated mandibles. When hunting, dragonflies catch prey with their feet, tear off the prey's wings with their sharp jaws so it can't escape, then scarf the sorry bug down, all without even needing to land.

Thankfully, most dragonflies can't bite humans. The vast majority of species don't have mandibles strong enough to break our skin. Only a small handful of large species are capable of biting, and they'll only bite as a defense.

3. They're Freaky Fliers

Few species in the animal kingdom can compare to the dragonfly's spectacular flying ability. The insects have two sets of wings with muscles in the thorax that can work each wing independently. This allows them to change the angle of each wing and practice superior agility in the air.

Dragonflies can fly in any direction, including sideways and backward, and can hover in a single spot for a minute or more. This amazing ability is one factor in their success as aerial ambush predators—they can move in on unsuspecting prey from any direction.

They're fast, as well, with some species reaching a top speed of 18 miles per hour. They're also known for their feats of endurance. One species called the globe skimmer (Pantala flavescens) flies 11,000 miles across an ocean in what's considered the world's longest insect migration.

4. Dragonflies Are All Eyes

If you look at a dragonfly's head, you might notice one thing in particular—or, rather, 30,000 things in particular.

The area of an odonate's head is composed primarily of its enormous compound eyes, which contain 30,000 facets, each bringing in information about the insect's surroundings. Dragonflies have nearly 360-degree vision, with just one blind spot directly behind them. This extraordinary vision is one reason why they're able to keep a watch on a single insect within a swarm and go after it while avoiding midair collisions with other insects in the swarm.

5. They Can Live Years Underwater

Dragonflies lay their eggs in water, and when the larvae hatch, they live underwater for up to two years. Actually, depending on the altitude and latitude, some species may stay in the larval state for up to six years. They'll molt up to 17 times before surfacing and transforming into the dragonflies we see in the air.

They are specially adapted for the aquatic life in this stage, with the ability to snag prey at lightning speed. They'll eat a large variety of food, including other insect larvae, tadpoles, fish, and yes, even other dragonfly larvae.

6. Some Lay Eggs in Saltwater

Relatively few insects inhabit the ocean, perhaps because they have trouble surviving in saltwater. That doesn't seem to bother some dragonflies, however. Certain species, like the seaside dragonlet (Erythrodiplax berenicei) can even produce offspring in environments saltier than typical seawater.

The seaside dragonlet is a standout species because its habitat consists of salt marshes, mangroves, and saline lakes. It's the only dragonfly species in North America (but not in the world) with a range that's restricted to salty habitats.

7. Dragonflies Are Beneficial to People

Dragonflies help humans by controlling populations of pest insects, especially those that threaten us most, such as mosquitoes and biting flies. A single dragonfly can eat anywhere between 30 and hundreds of mosquitoes per day.

Dragonflies also inspire us to create new technology—from drones to artificial visual systems—because of their incredible flight skills and vision. The least we humans can do to return the favor is support the conservation of their habitats so they can continue on for another 300 million years.

8. They Can Be Admired in Sanctuaries Around the World

Dragonflies need protection from the dangers humans have created, from pollution to habitat loss, and sanctuaries help with this. The U.K. got its first dragonfly sanctuary, the Dragonfly Center, in 2009. U.S.-based dragonfly enthusiasts can also admire them at the Dragonfly Sanctuary Pond in Albuquerque, New Mexico. This is the first sanctuary pond in the country and home to an amazing diversity of dragonfly and damselfly species. Another famous one is the Shimanto Dragonfly Park in Japan.