CHICAGO — Don't be alarmed if you see swarms of hundreds — if not thousands — of dragonflies all over Chicago this month.
The bugs, which almost always in August congregate in giant masses in the hundreds, can't sting because they don't have stingers. They also won't bother you, unless you try to hold one in your hand.
"There's nothing to worry about," said Doug Taron, the curator of biology at Peggy Notebaert Nature Museum and an administrator with the International Migratory Dragonfly Partnership. "It's sort of an urban legend."
The partnership uses citizen scientists to try and track and count dragonflies during their migrations north in the spring and south in the late summer. Unlike monarch butterflies, which travel to a few select trees in Mexico, no one knows yet where the dragonflies go, Taron said.
"We're still not sure," he said. "But people have really enjoyed participating in the [partnership] and watching dragonflies."
What is known is that there will be lots and lots of the bugs, which dine on mosquitoes and other small flying insects, zipping around Chicago this month. They travel along "water courses" like the Lake Michigan shoreline and the Chicago River because they don't like migrating miles out over open water, Taron said.
Last year showcased an especially epic swarm of dragonflies that originated from the Lake Michigan waters. Taron said those types of numbers, which blanketed the Chicago lakefront, are unusual.
Dragonflies spend most of their lives buried in the bottoms of waterways. They can live for years as nymphs, then they make their way up water vegetation. They rest on the top of water plant life as they emerge from their nymph skin and become an adult, only flying away after their wings dry and harden.
The adult dragonflies can live up to five months, Taron said.
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