Blood-curdling images show pillars of swarming mosquitos above Russia's Kamchatka region as they hunt for a mate.
The photos of swirling columns of mosquitos are causing a buzz online, but locals of Russia's Kamchatka Peninsula say the event is an annual "trouble" that darkens the sky every summer.
Aleksei Ponomaryov, the Kamchatka local who filmed the apocalyptic event, near Ust-Kamchatsk, told local news outlet Kamchatka-inform: "I left early this morning, and as you can see I ended up right in the thick of things. I can't say how high these pillars [of mosquitoes] were, it seemed like they rose up to the clouds." Ponomaryov said the swarms would form in towering columns, dissipate, then appear again within seconds.
According to a widely cited 2005 research paper on mosquito mating habits, such "tornadoes" are rarely observed swarms of male mosquitos seeking to leave with a female partner.
The nightclub-like scenario is described by researchers as male mosquitos clustering "in sometimes large numbers, forming nearly cylindrical swarms of several meters' height…. Single females fly into the swarm and are detected by their lower wing-beat frequency. Several males may arrive near the female, which departs with one of them from the swarm."
Previous observations of the phenomenon, which has also apparently been filmed in Argentina, note that the howling pillars of mosquitos tend to rise above visually distinct "swarm markers" on the ground "and usually keep station in reference" to the object. The Russian images appear to show the mosquito swirls forming above roads, possibly using puddles as markers.
Ust-Kamchatsk lies on the swampy banks of the Kamchatka River and is notorious for its summer mosquitos. Locals say the bloodsuckers are so aggressive in summer they will bite people who venture outside "even in a downpour" of heavy rain.
"We always have such trouble in the middle of summer, this time after the rain they came out," Ponomaryov said. "It seems to me that this year there are more of them than usual."