Gruesome or Just Boy Stuff?

So, as I was cleaning up the floor from the millionth mess of the day today I noticed a dried, red drop on the pergo.  As I examined further, I saw a few more drops and I realized in horror that I was actually following a trail of blood!  A terrifying mystery?  I called all three boys to the crime scene. 

"What is this?" I asked each of them, pointing accusatorily at the floor.  Blank looks on their faces. 
"It's blood!"  I say dramatically.  Blank. 
"Blood?"  one of them asks, puzzled.
"Yes, blood," I respond and begin checking them over.  No telltale bloody nose, no cut on the foot.  "Where did the blood come from?" Still blank. 
"Have any of you been bleeding?  Are you okay?  Why didn't anyone tell mommy?"  Nothing.  Then realization begins to dawn on the three year old.  I can see it in his eyes and I focus my questioning on him.
"Sam, are you bleeding?" 
"No, mommy."
"Are you sure?"
"I was bleeding."
"Where did you get hurt?"  Mumbles incoherently and gestures in the general direction of his lip.  Mystery solved.  He apparently bumped his lip, though there is no real sign of trauma and he didn't feel like it was important enough even to come get a magic mommy kiss.  Ahhhh.  It all seems to be okay now.  It's just boy stuff.