Angry Birds Swoop At People

(CBS) -- Beware of the birds – the red-winged blackbirds, to be exact.

There are reports around the city of these little things wreaking havoc on walkers and runners.

It's all part of the territory, CBS 2's Audrina Bigos reports.

When you're not looking, they dive-bomb, swooping down and pecking people on the head or banging them with their feet.

Sophie Lucido has felt the claws, twice, near the North Pond Nature Sanctuary in Lincoln Park.

John Bates, associate curator of birds for the Field Museum of Chicago, has an explanation.

"It's breeding season, and red-winged black birds across the city are defending territories," he says.

It happens in the summer. Bates says he's never heard of any injuries, but the extra protective birds do prey on certain people they recognize.

"So, if they think someone is coming by too often they may be able to identify the face of that individual and attack it more just because they think it's more likely to be a predator."

Don't fight back. These birds are protected under the Federal Migratory Bird Treaty Act.