The meteorologists who invented weather radar never expected to be studying bugs. But today they do.

There are 159 weather radar stations in the US. They look like giant golf balls on towers. There’s a rotating dish within the white sphere that sends radio pulses into the sky. When they meet something, some of the radio waves bounce back.

The radar reads the time and strength of the returned waves to determine the distance and concentration of the object they encountered. Like a cloud.  

As weather radar has become more sensitive, meteorologists began to receive readings of strange clouds. One was 80 miles wide, hovering over a mile high, before it suddenly disappeared.

They eventually realized it was a giant swarm of ladybugs; they fell off the radar when they dropped below 450 feet on the way to land.

Soon meteorologists were seeing more enormous clouds—sometimes hundreds of miles across—of mayflies, monarch butterflies and grasshoppers—all harmless.

But clouds of agricultural pests were also detected, like migratory moths that lay eggs on crops, which hatch into caterpillars that destroy the plants.

Meteorologists trained themselves to differentiate these pest clouds and alert farmers when bad bugs move into an area—so they can optimize pesticide spraying to protect their fields.

Another surprising benefit of technology in our daily lives.