Wierd Alien question?

OK i am open to the concept of aliens, its a little egotistical to believe we are the only thing in this universe or any for that matter with intelligence. Here is my question. There are thousands maybe hundreds of thousands of UFO sightings most can be explained some cannot. But what is the point? YOu fly from some distant place look around a minute and bamm u are gone again? Seems redundant. Also, radio waves and high freduency waves we are transmitting by the boatload literally. But never ever have we heard a peep from deep space or even an on earth UFO. What gives?