From the brains behind brains on, this is the moment of um.

Moment of um comes to you from APM Studios. I'm Anna Goldfield.

Um.

Our bodies are a wonderful and weird collection of parts that work together to make us tick.

But we don't always know how our bodies work or why they are the way they are.

And when people don't know something, they can come up with some pretty fun explanations.

Like, the other day, I was chatting with a friend who had just had a baby, and she called a birthmark

on the baby's skin a stork bite. Now, I know that her baby was not bitten by a stork,

but actually, I'm not sure I know what birth marks are in the first place.

It's a good thing Benjamin was asking about birth marks too.

Hi, my name is Benjamin, and I'm from Philadelphia.

And I would like to know what are birth marks.

A first mark. What are birth marks? A birthmark is a spot on your skin that is present from the moment that you're born. Hi, my name is Dr. Liz Farhan and I'm a dermatologist.

And that means that I'm a doctor who specializes in skin. So there's three main types of birth

marks. There's tan patches, moles, and growths of blood vessels. And they all just have really fancy

names. So the first type is a brown patch and we call it a cafe au lai macule, which means coffee

with milk because the person who named it

thought that it looked like a spot of coffee that had spilled. The second type of birthmark is called

a mole. The mole forms on the skin from mole cells growing into an area on the skin. These are

usually darker brown in color. They can be small or large.

And when these become more raised, they can even have hair growing out of them. The third type

of birthmark can be either a pink patch, which they can call a salmon patch because it looks

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