Blood is strange. It’s inside us all the time, yet the moment we see it on the outside, we panic. It’s dramatic, a little scary, and completely essential to staying alive. In this episode of Explain It Like I’m 5, Alex dives into why we have blood, what it does, and why it freaks us out so much.

You’ll learn how blood actually works—what’s in it, how it moves oxygen and nutrients around your body, and how it fights infections and heals cuts. We’ll also explore why blood is red, what blood types mean, and how much of it you really have. Along the way, we’ll uncover some wild facts about blue-blooded creatures, vampires, and why mosquitoes prefer certain people over others.

By the end, you’ll see that blood isn’t creepy—it’s incredible. It’s your body’s delivery truck, defense squad, and clean-up crew all in one.