No, it's not because of the axe murders.
My 4-year-old twins were on a time-out in their room for fighting when Catherine got a massive nosebleed (possibly from a kick in the nose by Elisabeth, but that allegation remains unproven). I thought all the screaming was just them continuing their usual carrying on. Nope, it was Catherine smearing blood on every available surface and Elisabeth getting horrified by it. It was utter carnage in there.
Had to go get out the carpet cleaner.... and wash the walls.... and all their clothes.... and the bedspread.... and the sheets..... and the bathroom and hall walls and floor....
Fortunately Catherine also discovered the way to take blood stains out of her new Ariel the Mermaid shirt. Dumping an entire 100-ounce bottle of concentrated liquid laundry detergent in the washing machine will do the trick, never fear.
Update: The bloodstains are murder to get out of the beige carpet. I used the upholstery cleaner machine when they were fresh, but they were still quite evident. This morning I scrubbed with a brush and dish detergent. They're faded but still visible. I hear club soda might help, that's the next step. Then I give up and live with bloodstains on the carpet. What exactly do the criminals use on CSI to get this stuff out? Bleach?