I fear they are looking for somewhere warm to nest.
I looked for the source of the infestation.
As you can see they are coming from the Internet.
I had a solution.
I've had these figures for at least ten years. I think I painted them up as soon as I got them as they didn't require much work... Wrong. Their bases were such that they easily toppled over. But now I have based them on washers and built it up with plaster and tried a bit of sculpting to extend the original base design. All finished. Challenge will be to use them in a game.
As with the goblins, I don't know the manufacturer of these figures. However a Google search found this site: Stuff of Legends. They have an image of these figures under "Alien Warriors #1" and attribute them to Leading Edge Designs with the sculptor being Bob Ridolfi with production date as "before 1994 to 1996" (whatever that might mean - I can't recall when or where I got them). It looks like there was quiet a range tying in with the second movie: