It's 1am, do you know where your kids are?

Late night check on the kids. All are fast asleep. But what had they been up to? Zadie looks like she crash landed

Zack is far from properly-aligned:
But where is the 3rd child? I look around the room and around the house in obvious places.
Closer inspection reveals some clues
Zoe is fast asleep, face down, arms down, knees up, under Zadie's bed