Millions of ladybirds formed a swarm so big that it appeared on radar.
The 80-mile swarm was spotted by meteorologists over Southern California on Wednesday.
The National Weather Service showed the swarm moving through the desert, around 70 miles from Los Angeles.
“The large echo showing up on SoCal radar this evening is not precipitation, but actually a cloud of lady bugs termed a ‘bloom’,” the National Weather Service’s (NWS) San Diego station tweeted on Wednesday.
It is reported that Joe Dandrea, a meteorologist in that office, had to call an observer in the San Bernadino mountains to find out the nature of the huge radar return.
He told the LA Times: “The observer there said you could see little specks flying by. I don’t think they’re dense like a cloud.”
They were spotted using next-generation radar were flying at between 5,000ft and 9,000ft, he said.
Ring Cardé, a professor of entomology at the University of California Riversdale, had one possible explanation.
He told Reuters it could be the case that a large population of ladybirds had been spread out over land in a mountainous area, and rising temperatures triggered their mass migration.
There are about 5,000 different species of ladybirds, also known as ladybugs, lady beetles or ladybird beetles, in the world.
The most familiar is the seven-spotted ladybird, with a shiny red-and-black body.
In many cultures, ladybirds are considered good luck.
And they are also seen as good luck for farmers, as they eat aphids and other plant-eating pests.
A single lady beetle may eat as many as 5,000 aphids in its lifetime.