Reasons Why Your Yard Is Swarmed With Dragonflies
Dragonflies, with their beautiful iridescent bodies and buzzing wings, are fun insects to watch as they zoom around your yard. Also, as one of the fearsome predators of the insect world, they are one of those bugs that you shouldn't kill in your garden since they eat many other pests, including mosquitoes, gnats, flies, and moths. However, while a few dragonflies in your garden are a treat to the eyes, you may be surprised if you wake up one day to find a swarm of hundreds or even millions in your area. So, what would cause a dragonfly swarm to hang out at your house?
As it turns out, having many dragonflies in your yard typically comes down to two things — water and food. This is because adult dragonflies live for a relatively short amount of time (one week to two months depending on the species) and, therefore need to quickly find enough food and water to complete their life cycle and lay eggs. If your yard looks like a suitable location, you may just catch the eye of a migrating swarm heading south in autumn.
Your yard has plenty of water
Dragonflies are typically found buzzing around water sources like lakes and rivers. This is partly because dragonflies spend the first year of their lives as nymphs living underwater before maturing into flying insects. So, if you live near a natural water source or have a pond or unchlorinated pool in your yard and see a sudden large group of dragonflies, this is likely because there was a big molting of new adults in your area. Dragonflies may emerge from their underwater stage and start flying anytime from late spring to early summer.
Alternatively, dragonflies may gather near water to mate and lay eggs. Female dragonflies prefer to lay eggs in standing water because the food source for dragonfly nymphs (mosquito larvae, worms, and tadpoles) is abundant there. This is why, if you want more dragonflies, it is often recommended to add water features like fountains and birdbaths. Although fountains and birdbaths will likely attract mosquitoes, they also luckily attract the predator that eats both mosquito larvae and adults, too.
Your yard has a spike in food
If you don't have a water source but still have a big swarm of dragonflies, then the reason for this is likely a sudden increase in the availability of dragonfly food in your yard — which can happen for multiple reasons. The first is that a period of rain or humid weather in your area causes a hatching of mosquitoes and dragonflies like to spend time where they know mosquitoes are.
However, you can also get a swarm if you have a large amount of other dragonfly food sources, like ants and termites. According to Iowa State University, dragonflies have been known to travel long distances to eat swarms of winged ants which emerge in late spring and early summer after a few days of rain. Dragonflies also love eating winged termites. So, if your yard or home has a termite problem, you may end up with a lot of these colorful predators.
Lastly, certain human actions can contribute to the disturbance of colonies of gnats and other little flying insects which can cause them to leave their hiding spot in the ground and create a bug ball in the air (perfect hunting for dragonflies). These activities can be as simple as mowing your lawn or moving a woodpile. However, you should never move a woodpile just to draw dragonflies as it is a favorite hiding spot of brown recluse spiders.