Quietly Watching

Imagine a World, far away in another Universe where a race of aliens exist. Over millions of years, unbeknown to them, we watch them grow and evolve and they settle different parts of the planet. We see that sometimes the different collections of aliens meet with each other and when they do, they fight. As time progresses the aliens develop more efficient ways of fighting each other and killing each other as one group takes over the part of the planet from another.
Time passes and the aliens develop ways of leaving the ground and they use this as a means of killing even more of each other and still we watch as thousands of years go by and tens of millions of aliens have been killed under out gaze.
Then the aliens build a rocket and manage to make the short hop to reach one of their moons, meanwhile on the planet the killing goes on and larger and larger numbers die.
Unknown to then we watch as they move out further into space to land on another planet, and then another, and them another until finally they find one they can inhabit. Then they find another one, then another one.      
We then have a decision, as the stronger, more advanced race, can we allow this breed of aliens, who have been murdering and slaughtering each other since time began, to expand out into the universe? What if they discover Earth? Would we want them here? Should we try and stop them?  
Makes you wonder if we are being watched by Aliens, how would they feel about such a race as us humans expanding out into the universe?
Just mention it as we landed on Mars recently and UFO sightings are up by around 50% this year. Probably just a coincidence. Probably.