From Aliens Below

Zipp doesn't highly acknowledge the fact that Pipp believes that there are monsters under her bed. At least not until she receives some unusual texts.

Pipp says there are monsters under Zipp's bed. Zipp doesn't care, isn't spooked by them, and doesn't even believe in them.

Except for when she got texts that prooved her wrong, and that would only haunt her for the short amounts of time she would remember it...