do pigs sweat?

Second Grader: "Mrs. P, do pigs sweat?"
Me:  "That's a great question.  I don't know.  Dogs don't sweat.  I don't know about pigs."
Second Grader:  "Because when I say 'I am sweating like a pig' I'm not sure if it is accurate, because I don't know if they sweat or not."

I love seven year olds.  The answer is pigs do sweat, but only a little.  They have to regulate their internal temperature by wallowing in mud.  Or at least, that's what I gathered from Google.