In many places, tree squirrels are extra busy these days. It’s time for them to collect nuts to prepare for winter! So we’re heading to a squirrel-themed adventure course and practicing a few of the skills they use to survive: gathering nuts, traveling in trees, and speaking like a squirrel. We’ll also learn about how squirrels evolved, and hear about some of their surprising relatives.

Plus, a mystery sound and a moment of um: what chemical in apples mixes with oxygen to turn brown?