So he prefers the floor

My child will not sleep in his bed. Its not that Micah just gets out of bed its that he really just wants to sleep on the floor. For the past two weeks I put him in bed and find him the next morning sleeping on the floor somewhere in the house. The other day he woke up from his nap and went into the kitchen and fell back asleep on the tile floor. The house is at a cool 73 degree with the central air and he usually sleeps in shorts pajamas without covers on so I don't think he could possible be too warm. I just don't get it or really know what to do about it. Its hard for me to believe that he is so uncomfortable in his bed, that he has to go sleep on the floor. Last night he was really a stinker and fell asleep on floor after 2 hours of putting him back in bed repeatedly. I have been thinking about not letting him take a nap so maybe at night he will be tired enough to just go to sleep. I guess I can just let him sleep on the floor but I want him to go to bed when told and not wander the house. I hate the thought of locking his bedroom door but it might come to that. I do know that I am not staying up until 11:30 again tonight fighting with him.