Once they do locate us, they are able to travel here and it is either trivially easy for them to do so, OR they REALLY need or want something that is here so that it is worth the massive amounts of energy it would likely require, or both: this is related to point #2 and is pure speculation
Once they are here there seems to me only two options — a) they wish to remain concealed or to hide their presence in some way, or b) they do not care about concealing their presence.
That species has technology beyond our wildest imaginations: Total speculation, and the Fermi Paradox and Great Filter theories have a lot to say about how likely this may be.
Someone is actually able to find us out of all the planets in the universe, which is about as likely as accidentally finding a specific grain of sand out of all the grains of sand on earth.