It's so interesting that some people can actually fall asleep on it. I tend to have this (flawed) assumption that we human beings are all pretty much the same, but these kinds of things throw water in the face of that perspective. When I'm on acid I can't imagine how it could be possible to fall asleep, and it seems like no one should be able to... but I've seen people do it.
I certainly can't while I'm peaking but 5-6 hrs into the trip when I'm coming down, I am so tired and bored that after some tossing and turning in my bed my mind just drifts to unconsciousness only to wake up at midday if I dose around midnight.
Next time I will trip during the daytime