Dragonflies have been on the Earth long before humans appeared. Their adaptability and resilience have kept them going over the centuries and today they're found on every continent but Antarctica. These fascinating insects have some truly amazing traits, like regulating their own body temperature and the ability to see in slow-motion. Let's take a closer look at dragonflies and what makes them so special. We'll also see some cool photos and learn about some common myths about them from around the world.
They Don't Sting
Dragonflies don't have stingers, so you don't have to worry about getting stung by one. However, they do have tooth-like serrations. So a bite is not entirely out of the question.
It's pretty unlikely you'll ever be bitten by a dragonfly, though. They're not aggressive, so the only reason for them to bite is if they're acting in self-defense. And even if one does bite you, it shouldn't hurt too much since they probably won't even break the skin.
Dragonflies Only Eat While They're In Flight
After a baby dragonfly emerges from its larval state and starts to breathe air, it must quickly learn how to hunt its food. They must be good flyers to survive, because they only eat prey they catch while they're flying. This means that if they can't fly, they'll starve to death.
They catch their prey by grabbing it with their feet. Harvard University did a study on dragonfly hunting behaviors and found that the insects caught 90 to 95 percent of the prey that was released into their enclosure!
There Are More Than 5,000 Known Species Of Dragonflies
According to Smithsonian Magazine, there are around 5,000 species of dragonflies alive today. These amazing insects belong to the order Odonata, which comes from the Greek word for "toothed." Adult dragonflies can be identified by their huge eyes and elongated bodies. They have two sets of horizontal and transparent wings that help them hover and zip around in that way only dragonflies can.
Dragonflies are common throughout the world and can be found on every continent except Antarctica.
Dragonflies Were Some Of The First Winged Insects To Evolve
To date, the earliest flying insects discovered are now-extinct creatures that are most closely related to the modern dragonfly. Scientists believe this evolution took place about 300 million years ago.
The oldest confirmed insect fossil is that of a wingless, silverfish-like creature that lived about 385 million years ago. Roughly 60 million years after that, fossilized records of insects became abundant. "For many millions of years you had nothing, and then just all of a sudden an explosion of insects," said Standford University researcher Sandra Schachat.
Some Dragonflies Migrate With The Seasons
Some species of dragonflies migrate with the seasons, with some of them traveling great lengths. The green darner, for example, travels as far as 900 miles from Canada to the Gulf of Mexico.
Migration is a multigenerational thing for dragonflies. The first generations leave the south in the spring and lay their eggs and die when they arrive up north. The next generation hatches there and heads south by September. The third generation stays in the south for their entire lives and their offspring start the whole cycle over again.
Female Dragonflies Have A Very Direct (And Surprising) Way Of Turning Down Males
Many types of animals are known to play dead as a method of self-defense. It's usually done to prevent themselves from being killed or eaten by predators. Female dragonflies, on the other hand, play dead to avoid having sex with undesirable suitors.
New Scientist reported on the phenomena and watched as female dragonflies plunged to their "deaths" when approached by unwanted males. Surely they could think of a more friendly way to say no!
Dragonflies Aren't Above Eating Other Dragonflies
Dragonflies are not picky eaters. A dragonfly will consume about 15% of its own body weight in prey each day, and larger species eat even more than that. In their aquatic stage, dragonflies eat many kinds of small animals such as tadpoles, small fish, aquatic insects, and other invertebrates.
As adults they also keep their diets varied, eating prey including mosquitoes, bees, flies, beetles, moths, and other flying insects... including smaller dragonflies. Hey, it's all about nutrition for these guys.
It's A Myth That They Live Just One Day
This is a common myth about dragonflies. Lots of folks believe that the creatures can only live for one day, but this simply isn't true in most cases although they do have pretty short lifespans.
According to Healthline, many dragonflies live for one to two weeks after emerging from the larval state, although some live to eight weeks or more. Most of their short adult lives are spent eating or mating.
Their Amazing Eyesight
As you might guess from looking at them, dragonflies have amazing eyes. Their multifaceted or "compound" eyes can have up to 30,000 facets, and they detect colors that are beyond what humans can see, such as ultraviolet (UV) light.
These special eyes are also sensitive to movement and are excellent at tracking objects. Dragonfly expert Robert M. Olberg of Union College puts it this way: “They can see you when they're flying toward you and still see you when they’re flying away.”
They Can Control Their Body Temperature
In order to fly, a dragonfly's muscles have to be within a certain temperature range. As with other cold-blooded creatures, dragonflies are able to raise their temperature by exposing themselves to the sun, which is why you might see them perched with their wings outstretched.
Bigger dragonflies can also use a technique called "wing-whirring" to warm themselves up. This is where they'll rapidly vibrate their wings in order to generate heat in their flight muscles.
Dragonflies Were Huge During The Paleozoic Era
Most modern-day dragonflies have wingspans of about two to five inches. Fossils of prehistoric dragonflies have been found with wingspans much, much bigger than that -- up to two feet. About 300 million years ago, during the Paleozoic era, giant dragonflies roamed the earth.
Their huge size was due to the planet's oxygen levels. In those times, Earth's atmosphere had roughly 50 percent more oxygen than it does today. Modern scientists have been able to grow super-size dragonflies that are 15 percent bigger than normal by raising them in special chambers that closely replicate the oxygen conditions on Earth 300 million years ago.
They Form A Heart-Shaped 'Wheel' When They Mate
Like many animals, adult dragonflies spend a lot of their time either eating or mating. They have a unique way of mating, with their bodies forming a heart-shaped "wheel" when they're in the act.
When two dragonflies get together, the male will grab the female at the back of her neck using specialized "claspers" on his abdomen. The claspers fit into grooves in her body. At this point, they can fly around together. Some species of dragonflies will stay in this wheel position for just a quick minute while others might stay in this position for several hours.
They Have Lots Of Enemies
It's a good thing that dragonflies are such quick flyers and have excellent vision, because there are plenty of natural enemies that would like nothing better than making a meal out of them. Predators that a dragonfly has to keep its keen eyes on include several types of birds, spiders, frogs, and larger dragonflies.
While in the larval stage, dangers are presented by frogs and toads, fish, newts, and Kingfisher birds.
They're Considered Good Luck In Many Cultures
As we've learned, dragonflies are really amazing creatures. For many reasons, they're also considered to be good luck in many cultures around the world. Dragonflies represent a variety of positive things to some people, including maturity, wisdom, power, courage, prosperity, harmony, and magic.
Many people consider it especially lucky when a dragonfly lands on a person and think it's a sign of positive changes and new opportunities coming. Has one ever landed on you?
Some People Believe Dragonflies Are Evil
Just as they're considered good luck by some people, there are plenty of other cultures that view dragonflies as evil. They have nicknames such as "devil's horse," "water witch," "hobgoblin fly," and "snake killer" in parts of Europe and are thought to be associated with Satan.
One old Swedish myth insisted that the devil used dragonflies to weigh peoples' souls, so if you saw one flying around your head it could mean that you were being placed on a hellish "naughty or nice" list.
They Might Have A Human-Like Power Of Concentration
Although dragonflies' brains are much smaller than ours, there's some evidence that the insects are capable of performing some pretty high-level tasks. LiveScience reported that dragonflies have exhibited something called "selective attention," where they screen out irrelevant information and focus on a single target instead.
That kind of attention span is usually associated with higher-level primates and is essential in a dragonfly's hunting. "Once the dragonfly has selected a target, its neuron activity filters out all other potential prey," said expert Steven Wiederman. "The dragonfly then swoops in on its prey — they get it right 97 percent of the time."
They Have Huge Appetites
Dragonflies are excellent hunters and have huge appetites. According to Harvard University researcher Stacey Combes, who researches dragonfly flight, they are bottomless pits when it comes to eating.
Combes related to The New York Times that she once watched a dragonfly consume 30 flies in a laboratory setting, and said that "it would have happily kept eating if there had been more food available." In the wild, dragonflies consume 10 to 15 percent of their own weight per day
They Keep Mosquito Populations Under Control
Adult dragonflies, which live on a diet of insects, help keep mosquito populations low. One single dragonfly can eat anywhere from 30 to hundreds of mosquitoes per day! Even before reaching adulthood and when they're still in the larval state, they also consume mosquito larvae in the water.
To take advantage of this natural mosquito control resource, The Science Times recommends that people can attract dragonflies to their gardens by planting a wide variety of trees and shrubs, especially water plants that grow near and in ponds.
Dragonflies Form Huge Swarms At Times
When migrating dragonflies stop to eat, they will sometimes form swarms as they hunt for smaller insects. Sometimes the swarms are so large that they even show up on weather radar systems!
Christine Goforth, an aquatic insect expert who heads The Dragonfly Swarm Project, says that the clusters can contain "anywhere from a dozen to millions or even billions of dragonflies flying together in these big groups." That's a lot of dragonflies.
Dragonflies Don't (Intentionally) Harass Horses
File this one under "dragonfly myths that aren't true." Many people believe that dragonflies go out of their way to irritate horses, but this isn't the case. Of course if you were to ask a horse how it felt, it might report feeling harassed when a dragonfly persistently flies around it, but the insect doesn't have any special interest.
And since dragonflies don't have stingers and rarely bite, it's not as if they're going to harm a horse in any way.
Dragonflies See The World In Slow Motion
As we learned, dragonflies see the world in a completely different way than we do. Their reaction time is so fast that they basically view things in what we would consider slow-motion. To put this into perspective, dragonflies see about 300 images per second. Humans only see about 60 images per second.
This means that dragonflies can see fast-moving objects that humans would completely miss, helping them ensure another tasty meal of insects.
Their Flight Capabilities Inspire Scientists
Thanks to their four independently controlled wings, dragonflies are remarkable fliers and can reach speeds of up to 35 miles an hour. They're able to hover like helicopters, can fly straight up and down, and even mate while they're mid-air.
These insects' flight capabilities are so amazing that they inspire engineers who make drones and robots. MIT professor Jonathan How said that "one specific advantage you get in four wings is the maneuverability and ability to pick things out of the air and hover and dart around." Pictured is a dragonfly shaped bio-robot at a 2017 conference.
Males Are Very Territorial
Male dragonflies are very territorial. They typically choose areas near water that are a good place for females to lay their eggs. The males patrol their claimed areas by flying around a "route" and looking for food and intruders.
Other males should stay away! If a male dragonfly of the same species flies into the territory, all hell will break loose as the "landowner" defends his turf. Dragonfly fights can get pretty brutal.
Dragonflies Spend Part Of Their Lives Underwater And Part Above Water
Female dragonflies lay their eggs in water. These eggs then develop into a swimming larval stage and are called nymphs. These nymphs live underwater and shed their skin many times as they grow.
Once it reaches the end of its larval stage, the dragonfly crawls out of the water and its exoskeleton cracks open. Then the insect's four wings come out. It takes several hours or days for the exoskeleton to dry out and harden.
Don't Worry; They Can't Sew Your Mouth Shut
Yes, this is actually something that people believe(d). One of the largest types of dragonfly is known as a "green darner," because of its resemblance to a darning or sewing needle. There's a scary old European myth about them that people would tell their children to keep them from misbehaving.
The myth said that dragonflies would sew your mouth (or eyes, or ears) shut while sleeping as a punishment for wrongdoings. Some people are still told this story as children today! It's definitely not one to worry about. Dragonflies are clearly not able to sew anything, let alone human skin.