When=20one=20species=20interfaces=20with=20another ,=20the=20more=
=20advanced=20typically=20takes=20advantage=20of=2 0the=20other.

We=20have=20only=20to=20look=20at=20interactions=2 0on=20Earth=20to=
=20confirm=20this.

Advanced=20aliens=20:=20"=20human=20hors=20d'oeuvr es=20anyone=20?=
=20"