The Drake equation is pure hoakum, not science.
The Seti project has not come up with much, by the way, and it appears more and more likely that we are the only ones out here who are alive and who can communicate.
Is their life in other planetary systems? Probably. Very rare and probably only at the viral or bacterial level.
It is possible because when large asteroids have hit our planet great amounts of dust were blown into space. Some of the dust being full of microorganisms may have landed somewhere and in the least the remains could be discovered. I am sure if current scientist found evidence of the remains of one microorganism they will rejoice greatly that evidence has been found that life has evolved on other planet.
The problem is the distance between life bearing planets. Let's say the closest is 10 million light years away. A civilization would have to evolve to the point where it's understanding of the physical universe and it's technology advance to the point where it can embark on a minimum 10 million year voyage to earth at the speed of light, which all experts agree is impossible. Now this also requires that we occupy earth for at least 10 million years for them to know we are here and another 10 million for them to get here.
On second thought, maybe they did come here to study the dinosaurs but they become extinct before the trip ended. They are still here, explains the UFO sightings, but find us completely uninteresting.