You know that scene in the J.J. Abrams Star Trek movie where Nero was walking in ankle-deep water on his ship to get to a restrained Captain Pike? What do you think was in that water?
Some people--myself and the members of the message board I frequent about the topic--maintain that life on earth actually developed from rest stopping aliens who couldn't hold it until Jupiter.
Aliens would HAVE to expel waste somehow, so pooping is most likely if they are a higher lifeform. But who knows...perhaps they don't actually eat anything, thus making pooping unnecessary. Maybe they are like Ents, walking sentient plants who thrive on photosynthesis.
I believe alien excretions manifest as an energy field, which they then harness as a form of wireless bioelectromagnetism to power their appliances and vehicles and so on.
I always did suspect Willie Nelson was not of this earth. [image=http://www.commondreams.org/headlines06/images/0209-01.jpg] --> [image=http://www.availableimages.com/images/pictures/2002/men-in-black-ii/aph_5.jpg]
