Settling earthlike exoplanets or earthlike exomoons is colonizing another earthlike world. Modest numbers of extraterrestrial intellegence individuals can coexist without problem with modest numbers of human colonists since knowing that there is an abundance of other worlds would eliminate all exploitiveness. If it is Mars like, little terraforming can be required. No terraforming would have to be required on truly Earthlike worlds because it already has every thing for it to support life as we know it. If the earth like world is in a deep ice age, then colonization would be very different.