Blue Boobs

"Mummy! Your boob is blue and green!"
"Yes, that's the blood. You can see it through the skin."
"Why is it blue?"

Ummm, well. I've explained a lot of science simply before, but she's 3.

"Blood takes things around the body that it needs. So down to your feet and everywhere. When it's dropped everything off and runs out it turns blue. Then it has to go back to Mummy's chest and get some more."
Looking at my chest, "There must be little people in there."