Actually I don't think they (if they exist) even know we are here.
I'm one who thinks the misnamed "Fermi's Paradox" is a serious problem for the hypothesis that there are advanced extraterrestrial civilizations. (I say "misnamed" because the Fermi Question is not a paradox. It's a reductio argument against the view that advanced extraterrestrials exist.)
All it would take is one E.T. civilization in our galaxy to have reached technical sophistication several million years ago. This civilization could send little green explorers out in flying saucers, or build self-replicating robot probes. Either way, assuming the travelers only go v<.1c and supposing that it takes 100,000 years from the time the travelers arrive on the new world to the time a new robot or people vehicle is sent out (a very conservative estimate), the original civilization will have the entire galaxy populated in a little over ten million years.
Consider that the earth is about 4.5 billion years old, and the galaxy itself over ten billion years old. If, in fact, the conditions for the development of technical civilizations in our galaxy really are favorable enough for there to be some E.T.'s around sending radio broadcasts then why hasn't at least one flying saucer made its way to earth by now? Why isn't there at least one robot probe in our vicinity which has detected us?
I am skeptical of the premise of radio SETI, in other words. It's hard to understand the view that there are several advanced E.T. societies around transmitting messages of peace and good will but none have yet managed to show up in our neck of the woods in person or through their robot surrogates. I'm more willing to believe that we are the only technical civilization ever to exist in our galaxy than I am in that hypothesis.