(CNN) Hordes of dragonflies are showing up on weather radar and making things interesting for weather forecasters in the Eastern United States.

It's not their fault -- the flying insects are just heading south to escape the coming cold weather.

JUST WATCHED Time-lapse: Dragonfly breaks out of skin Replay More Videos ... MUST WATCH Time-lapse: Dragonfly breaks out of skin 01:01

The National Weather Service office in Wakefield, Virginia, tweeted radar imagery on Monday that showed strange, cloud-like masses over parts of Virginia and North Carolina.

Bit of a radar conundrum today. No rain around the region with decent returns on radar. Usually we'd think we're seeing bugs. Dual polarization radar products argue otherwise and some of these returns are above 10,000ft 🤔 pic.twitter.com/ofE6cxsZIg — NWS Wakefield (@NWSWakefieldVA) September 16, 2019

Mike Dutter, the science and operations officer for the Wakefield office, said weather radar is sensitive enough to detect tiny droplets of rain, so it's not unusual for it to also pick up dust, flocks of birds or insects.

"It doesn't surprise me that we're seeing this," he said. "The thing that's interesting is how widespread it is. It seems like numerous radars on the eastern third of the country are seeing it."