The word hibernation is often used in reference to deep sleep, but what is it really? What kinds of creatures hibernate? How does this demonstrate the...

Cells are the basic units of life, and in some forms they are actually organisms. What is a cell? What goes on inside of a cell? Did all life come from...

Try to get to the end of this episode without squirming! Almost everything on earth has some kind of parasite living inside of it—including humans....