Spencer: "Mommy. I know what milk is."
Me: "What is milk?"
Spencer: "Cow See-um."
Me: "Cow what?"
Spencer: "Cow See-um."
Me: "Cow what?"
Spencer: "COW See-um!"
Daddy: "Calcium."
Colin: "It's cow juice! That's why they call it Cow See-Um!"
Me (thought bubble): "Oh my good heavens."