Being that it is so small it will be difficult to find. I would look everywhere, including inside of shoes and such. Its very possible that it is moving when you are not looking. Tonight you could try putting a heat lamp where he can access it if he gets cold, along with a little food and water. Best if its a red light. Or, turn off all of the lights in the room so it is dark and search for it with a flashlight. My guineas don't flee as much when its dark since they can't see. This may also help you spotlight it, since sometimes when you are looking at the big picture its hard to see the details, so to speak, and it could be that at one point it was right in front of your eyes and you didn't notice it because of other items in your field of vision.
