Subscribe | UPI Odd Newsletter Subscribe YEKATERINBURG, Russia, Aug. 22 (UPI) -- Massive numbers of blood-sucking insects swarmed together in a Russian city to create a series of "mosquito tornadoes" on the horizon. The video, filmed Aug. 13 in Yekaterinburg, shows the mosquitoes gathered into huge groups around sunset. Advertisement The swarms form into spiral-like clouds that resemble tornadoes spinning in the evening sky. The filmer said each "mosquito tornado" is composed of millions of the insects. Read More New TV available in India purports to repel mosquitoes with ultrasonics Tech vlogger covers iPhone 6S -- and unlucky mosquito -- in hot tar