White-breasted Nuthatches aren’t the toughest birds on the block — but when it comes to their nests, they know how to put up defenses. Squirrels could easily duck inside a nest cavity and gobble up the eggs. That’s why you might see nuthatches sweeping around their nest hole with a beetle or other insect. It’s thought that chemical compounds from the insect smell bad to squirrels, driving them away. And if that doesn’t work, nuthatches try to make themselves look as big as possible.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.