What do the aliens want?

There are many potential answers offered by many people.

Common answers include:
* they want to hybridize with humans and thereby extend their scope, and possibly extend their diminishing biological capacity
* they want to feed off human energies (such as emotion)
* they want to help humans develop and eventually join the many other species that, presumably, are active in our galaxy (and perhaps beyond)
* they (the aliens) are not extraterrestrials but are a plot by some covert human group that is using advanced technologies to intentionally simulate alien abduction in an effort to strike fear into humans and thereby bring about popular support for some military force
* they want the Natural Resources of Earth
* they see the Earth as a zoo and don't want humans to destroy it