March is here, and that means mother raccoons would like to turn your chimney into a maternity ward.

Raccoons often choose chimneys to have their litters because they provide quiet and tight quarters where they aren’t likely to be bothered by predators.

To make sure raccoons don’t make families in your chimney, the Humane Society of the United States suggests first attaching pieces of yarn over the top of your chimney and check it 48 hours. If it’s moved, chances are you already have a resident raccoon.

If the chimney is raccoon-free, purchase a chimney cap, which costs between $25 and $45 at hardware stores and is easy to install.

If a raccoon already has taken up residence, don’t start a fire in the fireplace to smoke the animals out. They’re slow climbers, and they’ll probably asphyxiate.

Instead, gently “harass” the raccoon to convince it to go elsewhere. Placing a loud radio near the fireplace, shining bright lights and wafting strong odors like ammonia near the fireplace should do the trick.