Bo: There's a monster outside my room, can I have a glass of water?
Graham Hess: What are you thinking about?
Bo: Why do you talk to Mom when you're by yourself?
Graham Hess: Makes me feel better.
Bo: Does she ever answer back?
Graham Hess: No.
Bo: She never answers me either.
Graham Hess: It's happening.
Graham Hess: Swing away Merrill. Merrill... swing away.
Morgan: I think God did it.
Officer Caroline: Merrill... how's work at the gas station?
Merrill: Stimulating.
Graham Hess: Everybody in this family needs to just calm down and eat some fruit or something.
Graham Hess: The police are here. I am with them. I am a police officer. I just want to talk with you. We know all about the hoax. We already took some of your friends downtown in a paddy wagon. Just tell us your name and why you did it, and we'll give you the same deal we gave the others. Don't throw your life away, son.
Morgan: It's not contaminated, you don't even know what that word means.
Morgan: If you're gonna make fun of it, then forget it.
Bo: This is serious.
Graham Hess: I don't know what got into me.
Morgan: There are pictures. Dr. Bimbu, one of the authors of the book.
Graham Hess: Bimbu?
Morgan: Dad.
Graham Hess: I just asked his name.
Morgan: You had a tone.
Merrill: The nerds were right.
Graham Hess: Isabel, you are going to feel very silly when this turns out to be make-believe.
Tracy Abernathy: I swore 37 times in the last month. I said the 'f-word' a couple of times, but it was mostly 'shit's and 'bastard's. Is 'douche bag' a curse?
Graham Hess: I suppose it would depend on its usage.
Tracy Abernathy: How about "John you're a douche bag for kissing Barbara"?
Graham Hess: It's a curse.
Tracy Abernathy: Oh, well then it's not 37 times it's 71 times.
Colleen: Tell Morgan to play games, it's okay to be silly.
Graham Hess: I will.
Colleen: Tell Bo to listen to her brother. He'll always take care of her.
Graham Hess: I will.
Colleen: And tell Graham.
Graham Hess: I'm here.
Colleen: Tell Graham... see. Tell him to see. And tell Merrill to swing away.
Graham Hess: See this is why we're not watching TV, people become obsessed.
Graham Hess: You're scaring your sister.
Bo: I'm already scared.
Officer Caroline: What kind of a machine bends a stalk of corn without breaking it?
Graham Hess: It can't be by hand, it's too perfect.
Bo: Are you in my dream too?
Merrill: There are a lot of things I can take, and some things I can't. But what I can't take is when my older brother, who's everything that I want to be, starts losing faith in things. I saw that look in your eyes last night. I don't ever want to see that look in your eyes again.
Merrill: Move children! Vámanos.
Answer: It's left unclear, though the film proposes several possible theories, and there are other possible explanations as well. One major theory brought up in the film is that the aliens were there to acquire Earth's resources after using up their own. Another theory proposed at the end of the movie is that the aliens wanted humans for whatever reason, as a radio DJ mentions seeing his friend's family being dragged away. There is also a very popular fan theory that the aliens are supposed to represent demons that are merely there to create chaos and test the moral strength of humanity, as the film is ultimately about Graham losing and then regaining his faith, although this is more subtext than anything and may not be literally true.