When you really think about it, why would they be hostile? If humans encountered another race, our first instinct (as a whole) would hopefully be to study and learn from them, not destroy them. Of course they aren't humans, maybe some warring clan system (been watching/reading way to much sci fi...), and if in that case, I doubt they would have the technology to actually dent the human population.
Ok.. A bit of history.
Stone tools.. The first technology we had, were weapons firs, other uses came later.
Fire .. I bet they used it to kill each other and animals before using it to cook.
Any technology, you name it.. Almost everything is made for war.
War.. Makes people desperate, people die but technology increases.
A hunter is always more advanced than the prey..
Any specie that's advanced will either be powerful predator in its origin, or subservient to or weaker than another powerful one.
Now, let's say, they don't need to study us, they just need adna sample to analyze our biology and that's enough for them. They'd just replicate the data, compute and process it.. Then kill us...
You think they'd study or culture? Ha! History is filled with examples of the winners destroying the losing cultures, not the other way round.
they'd rather eliminate an inferior culture or ideology, rather than leave it alone.
Why bother to let a specie rise?
An example..
Why do you kill snakes?..
We would be like animals or playthings to them.
When they can travel light years, they will be sufficiently advanced.
Humans are disgusting in general, others kill for food, we kill for pleasure.
Why do you expect others to be different?
The best, we would become a subservient race.
The worst, we become toys.
