You walk out your front door, minding your own business, when a bird swoops in for a flyby. Or there's a certain spot on your walk around the neighborhood: When you hit it, a bird zips by and dive-bombs your head.

Don't take it personally. It's not you; it's spring, a time when birds get very protective and territorial about their young. The bird isn't attacking; it's just trying to scare you away.

"It may seem like it's an offensive behavior and some people might find it offensive, but it's actually a defensive behavior on the part of the bird. It's simply trying to persuade a potential predator away from the nest," says Bob Mulvihill, ornithologist at the National Aviary.

Birds are most defensive when they have young in the nest, typically from the time they hatch until they fledge and leave the nest, Mulvihill says.

"In some cases, it may continue even until they fledge for a short time for a few days or a week. They aren't very strong fliers and aren’t very capable to escape on their own from a predator."

According to the U.S. Fish and Wildlife Service, the dive-bombing behavior can be an effective scare tactic, although the birds are unlikely to hurt you.

Mulvihill agrees.

"Flybys are the rule. I've personally heard about cases where people have been bumped and the bird has actually made contact with a person, but it's risky for the bird to engage with anything that can turn around and swipe it or claw it," he says. "They don’t want to go toe to toe with you."

Working as an ornithologist, Mulvihill has had a lot of birds dive-bomb him over the years, and he says he's never had one make physical contact.

"It's all bluff. It works pretty well if you're afraid of them."

Which birds dive?

Northern mockingbird with mouth open Mockingbirds are especially protective of their babies and will ward off predators (like you) through flybys. (Photo: Renee/flickr)

Mockingbirds are most known for their dive-bombing behavior, says Mulvihill. Swallows are also known to use the swooping scare tactic to keep people, dogs, cats and other potential predators away from their nests.

The U.S. Fish and Wildlife Service points out that many raptors also aren't afraid to make close brushes with humans during nesting season. Red-tailed hawks, red-shouldered hawks, Cooper's hawks and peregrine falcons are likely to show more assertive behaviors when protecting their nests.

Some birds don't dive-bomb, but use another type of behavior to protect their young, Mulvihill says.

"They'll feign injury and drag a wing on the ground, limp along, call pitifully, limp ahead of you. When you're far enough away from the nest, they fly away," he says. "They do this little act to try to get you to look at her instead of the nest. It's an impressive distraction display."

What to do

bird nest built on porch light Avoid this front door if there's a protective mother guarding her nest. But then take it down once the babies are gone. (Photo: John E Heintz Jr/Shutterstock)

If you have a nest near your house being guarded by a dive-bombing parent, the best thing to do is give the birds some room until the babies are gone.

"The nesting cycle is so short you can wait it out. It may be just two or three weeks," say Mulvihill. "They're not capable of inflicting any pain or harm, so notice it, be a little bit fascinated by the behavior, but ignore it. In most cases it's not a threat to you."

You may want to use another entrance or avoid a certain part of your yard, if you can. If you really are taken aback by the flybys and can't avoid the general vicinity, carry an umbrella or wear a hat.

It's illegal to move a nest when there are eggs or young inside it.

Once the baby birds have left their home, you can remove the nest so the parents won't return to that spot next year.

The U.S. Fish and Wildlife Service suggests making the area unattractive for a future nest. If the spot is on your porch, cover a ledge with netting or some other obstruction to keep birds from nesting. If you have a fan, keep it running on low until nesting season is in full swing.

Or just let it alone and realize you'll be experiencing an interesting part of nature each spring, Mulvihill says.

"Birds are genetically hardwired to protect their investment ... which are baby birds."

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.