watch 01:24 The Loop (TV) Do you like this video? General References Appearances Gallery Quotes Credits ◄ A Load of Trouble Signs of Intelligent Life Mr. Bart Krabappel! ► D'oh! This article is a stub. You can help the wiki by embiggening it. Template:Bart Simpson Comics Stories 101-150/References Retrieved from "https://simpsons.fandom.com/wiki/Signs_of_Intelligent_Life/References?oldid=514816" Categories: Stubs References Trivia Goofs Real World comics Community content is available under CC-BY-SA unless otherwise noted.