Millions of ladybirds have formed a swarm so big that it appeared on radar.
The 80-mile swarm was spotted by meteorologists over Southern California on Wednesday.
The US National Weather Service showed the swarm moving through the desert, around 70 miles from Los Angeles.
It said the large echo showing up on radar was not precipitation - but a cloud of ladybugs.
This is termed a 'bloom', it added.
The large echo showing up on SoCal radar this evening is not precipitation, but actually a cloud of lady bugs termed a "bloom" #CAwx pic.twitter.com/1C0rt0in6z
— NWS San Diego (@NWSSanDiego) June 5, 2019
Some Twitter users saw the lighter side, asking: "So do we need an umbrella or...?" and "Well, better than locusts".
"Can you give ladybug updates? Like, where are they going?" another person asked.
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 ladybugs 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 ladybugs, also known as known as lady beetles or ladybird beetles, in the world.
The most familiar is the seven-spotted ladybug, with a shiny red-and-black body.
In many cultures, ladybugs 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.