Now a days there have been a lot of evidence of their existence. They have been among Humans since Ancient times.
Since humans begin to "play around" with NUCLEAR ENERGY in the XXth Century... they have been paying close attention on Earth. They are here to help Humanity NOT TO DESTROY THEMSELVES.

There have been many "disclosure" events. This is only one of them. From the Ex Prime Minister of Defense from Canada; watch what he has to say about this:

[link to www.youtube.com]