Do you think we are alone in the universe?

Are we alone in the universe?  There is an enormous amount of room in outer space, so what is the probability that humans are the only form of intelligent life in the whole universe?  Many people have reported seeing aliens and some have told their stories of how they were abducted by aliens.   Some may argue that it was their imagination, they seen a weather balloon or maybe it is true.

Now if there is such thing as an alien, what would make it an alien?   Let’s keep the definition simple for what an alien is.  Let’s consider them to be any living being that are capable of creating tools and machines.  These beings should have the ability to one day (or already) be able to achieve some form of space travel.

Some may wonder if they are already out there watching everything that humans do.  Perhaps there is no such thing, and earth is the only place in the universe that supports life.  Maybe there are aliens out there, but just are unable to travel the vast distance to visit us.

What are your thoughts and reasons behind why you do or do not think there are aliens out there?