Stuff that is MHTG:
Canned ham, the UN, ski masks, internet browsing history, plastic water bottles, pubic hair, affirmative action, Justin Beiber.
Any object or place that leads you to take a "surprise" nap.
Oftentimes, one wakes up completely bewildered or shocked that they fell asleep in a nap trap, even if they have fallen into the nap trap before.
Example 1:
3PM on Sunday
Me: Hmm. I guess I'll just sit here on the sofa and watch TV for half an hour.
4:20PM that same day
Me: *Opens eyes* Crap, did I just fall asleep?
Roomie: *Walks by* Dude, you know that couch is a nap trap.
Example 2:
No wonder I am failing calculus, that warm classroom is a total nap trap.