In this encore mash-up episode, we revisit some fascinating facts that will help you get to know your nose. Why does the sun make some people sneeze? And where do boogers come from anyway? Plus: A brand new moment of um answers the question: "Why do sloths move so slow?"

What is a generation and why do we have them?
28:02

Why doesn’t stomach acid burn right through us?
28:51

Can a spider eat a wasp?
30:24