MINNEAPOLIS (WCCO) – Thousands of the big black birds are suddenly being spotted in the Twin Cities, perching on trees and blanketing the sky.

It’s quite the sight.

“We were driving home at dusk last Friday heading towards Lake Street and I looked up in the sky, and I saw 10,000 crows. I mean more crows than I’ve ever seen in my life,” said Nancy Mulloy, of Minneapolis.

Mulloy and dozens of others have recently asked us why there have been so many crows around in the metro.

Kirk Mona, a naturalist at the Warner Nature Center, says the sight is actually nothing new.

“It’s been going on for a lot of years in the Twin Cities,” he said. “Crows have always gathered in the winter.”

Usually, crows roost in rural areas. But in the winter, they come into downtown for the same reasons people do — to eat, exchange information and find a mate.

“If you come into the city, it’s well lit, safety in numbers,” Mona said. “If a predator approaches, the alert goes out and all the birds know right away what’s going on.”

A flock of crows is called a murder, a name that leaves some uneasy, especially after Hollywood thrillers like “The Birds” and “The Crow.”

“Crows aren’t a bird you need to worry about,” Mona said. “There really aren’t any birds people need to worry about while walking around with their dogs. It’s actually quite fun and quite a unique experience to be out when there’s that many birds.”

Don Davies walks his dog and a neighbor’s through Loring Park in Minneapolis daily. He says the birds don’t arouse fear as much as frustration.

“It’s the mess they make,” he said, “especially if you park your car outside under a tree.”

Bird experts say the crows will pick a mate in March and spread out to build their nests. That’s also when food becomes easier to find.