D: Congratulations on completing your PhD in Zoology this week, Yael. That makes six advanced degrees for you and eleven for me.

Y: Well, we want to make sure Moment of Science listeners know they're getting only the best information.

D: You must be proud.

Y: I'm happy as a pig in mud.

D: Hey, there's a good moment of science.

Y: Why are pigs happy?

D: No, why do pigs roll in mud? I mean, you'd never catch me doing that!

Y: But I have seen you sweating.

D: Well, I guess so . . .

Y: Ever seen a pig do that?

D: Have I seen a pig sweat? Well . . . I guess not. But what's your point?

Y: Pigs are doing the same thing when they roll in mud that we're doing when we sweat. They're staying cool.

D: Staying cool?

Y: Sure. Humans get rid of excess heat by sweating. When the sweat evaporates it carries heat energy away from your body, which is why a sudden breeze feels cold when you are wet. Pigs don't have sweat glands. They have to add moisture to their skins in order to get it to evaporate and take away heat.

D: And mud has moisture in it.

Y: It sure does; otherwise it would be dry dirt. Anyway, mud may be a pig's only option if it's inside a pen. If there were water to splash in, the pig might choose that to cool off.

D: And that's something even people do!

Y: At every swimming pool in town.