Just curious, did they use a different font for each alien's speech? That's an interesting way to do it if so. Some books use the old tried and true method of starting a new paragraph everytime a different character speaks. One character speaking per paragraph, in other words. That of course works best with two characters, but creates a lot of paragraphs. Others use "CHARACTER A said, 'blah blah blah.'" or something similar, but that gets a bit old after a few pages.