If humans do find ‘intelligent life’ on another Skull wearing bandana Atlanta Braves Baseball team shirt planet, that life won’t be very smart. Any intelligent life would make sure that they weren’t found by humans, or if some humans did find it take any and all measures necessary to prevent that knowledge from being transmitted to any other humans.
One has only to look at what humanity in general has done Skull wearing bandana Atlanta Braves Baseball team shirt to its own kind, although of a different race, after they discover them for the first time. Eventually one group or the other is devastated or destroyed as a civilization. Would you willingly invite/allow anything like that into your home. If they can cause such devastation to their own kind, what would they do to a newly found species.