00:55 Bugs, Bats, Flies Caught on Weather Radar Meteorologist Ari Sarsalari has a few of the more interesting and gross things sometimes caught on weather radar.

In a scene worthy of an Indiana Jones movie, a swarm of untold numbers of mayflies descended upon an Iowa patrol car traveling across a bridge over the Mississippi River this weekend, forcing the bridge's brief closure Saturday night.

The bugs were so innumerable -- perhaps millions of them buzzed just outside the car's window, and many had invaded the car's interior -- that the officer was forced to stop mid-way across the bridge.

Iowa Department of Transportion officials posted a video of the encounter on the Savanna/Sabula bridge on their Facebook page over the weekend, noting that the insects are at the height of their hatching season on the Mississippi.

The swarm of bugs was so thick that it "covered the bridge, making it very slick," the department said, noting that supervisor Dick Banowetz "said the flies were ankle deep on the bridge," forcing them to plow it. Once his crew had finished plowing, they poured sand on the bridge to ensure vehicles would have traction.

Also known as shadflies -- or Ephemeroptera to scientists who study them -- these aquatic insects hatch in enormous numbers, usually in the spring.

Because they are attracted to light, they swarm near car headlights and into houses and other buildings around riverside towns, often forcing "local authorities to deploy snow clearing vehicle[s] to remove their rotting corpses," the Freshwater Blog notes .

Iowa DOT officials say they plan to keep the Sabula bridge's lights off at night, the Dubuque Telegraph Herald newspaper reports, to reduce the buildup of mayflies there, as the hatching period is expected to last for at least another few weeks.

Officials say motorcycles especially need to use caution, as two lost traction Saturday night on the bridge while trying to navigate through the crush of insect bodies on the bridge. Thankfully, no one was hurt.

“Biggest thing I noticed was after cars were stopped and sitting for so long while we’re trying to get cars moving again is they were probably piled knee high in front of their headlights from just sitting there,” said Reserve Officer Stephen Thayer of the Sabula Police Department in an interview with WHO-TV .

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