We infest the planet

Why exactly do all the aliens seem to come to Earth? Or, more specifically, superheroes of Earth or invasions of Earth? I'm not entirely sure about this but I think there are two reasons. One, we infest the planet. There are billions of us all over the planet and we keep reproducing. Very big harvest for aliens! Also, according to these comics, there is a ridiculously large amount of superpowered people here. Something that confuses me is why aliens would come to these people -- seeing as there are probably other people who could do the same sorts of tasks?

So saith a friend's child. Hell of a good question, really. Since aliens by definition can travel through space, and thus can choose to go anywhere, why do they all come here?