Some unusual movement on weather radar caused staff at the National Weather Service-Duluth some concern that there was a major fire in the rural Northland.
Turns out ... it was ducks.
The NWS said the image seen on Wednesday morning was traced to the Rice Lake National Wildlife Refuge, which is found between Mille Lacs Lake and Duluth.
"We contacted someone there and it turned out they were doing a waterfowl survey and they estimated 600,000 ducks were in the air," the NWS tweeted.
Rice Lake National Wildlife Refuge is operated by the U.S. Fish and Wildlife Service, and is a haven this time of year for ring-necked ducks heading on their fall migration.
In fact, the refuge holds the Minnesota record for the most waterfowl observed in one location, when more than a million were observed there in October 1994.
This kind of radar anomaly caused by the animal world isn't all that rare
We wrote earlier this year how a huge blue mass on the radar in Duluth this past June was actually seagulls and lake gulls flying south.
In 2017, another blue mass that showed up on radar in southeastern Minnesota showed hundreds of thousands of mayflies hatching for the season.