Too many legos to sleep

At 3am Calvin woke me up and said he had to go to the bathroom. Fine...except he went to his bathroom and not mine. At 3:30 I realized he hadn’t come back so I go to find him, expecting him asleep on the toilet. He was in his room with the light on building legos. I told him he had to come back to bed and he didn’t want to, but eventually I convinced him. I’m not aure when he got up again, but around 5:15 I woke up and noticed he wasn’t in bed. I again found him building. What he had been working on at 3:30 was now done and he wa playing with it, so I have no idea how kind he had been up. But he fought me on going back to bed again. He said he liked building at night. He took a nap at schoolx