They make up everything. Credit to from an askreddit thread about what not to trust.
Because once you go to sleep, you can't trust either of them to not sneak out.
Because he never spills the beans
9 3/4 *Credit goes to a tee shirt I saw. I'm not that witty.*
Because he has his own shoulder to cry on. Edit: all credit goes to /u/Earleebird who posted it in a comment in /r/oldschoolcool
Quark! Quark!
Because they make up literally everything