Their origin is unknown.
They are often seen near (or flying by) volcanoes. (Identified due to the exquisite nature of their ships)
They have never contacted Humans and there are no reports of violence or abductions.
Even though they are discreet their presence on Earth is frequent and they do not try to hide from view. There are several contradictory reports about their appearance.
Last sighted: Off the coast of Norway, in 2000.