Ben gets stung by a Griever while he’s out in the Maze, off‑screen, during a daytime run; the movie never actually shows the sting happening, only the aftermath when he returns infected.

Quick Scoop: What Happened to Ben?

  • In the first Maze Runner movie, the Gladers later say that Ben was “stung in broad daylight,” meaning it happened while he was out in the Maze, not at night.
  • The creature that stings him is a Griever, the biomechanical monsters that roam the Maze and inject a painful, mind‑warping serum.
  • When Ben comes back, he’s already infected and acting violent and delirious, which is why the others restrain him and discover the black, diseased sting mark on his chest.

Why You Never See the Actual Sting

  • The film skips the actual attack and only shows the consequences, so viewers just see Ben post‑sting losing control and attacking Thomas.
  • This “off‑screen” sting is often talked about in fan discussions as a bit of a plot gap, because no one clearly explains how he managed to escape a Griever alive after being stung.

In-Story Explanation vs Fan Talk

  • In‑story, the simple explanation is: Ben was out in the Maze, a Griever ambushed and stung him, he somehow got away, and the infection got worse once he was back in the Glade.
  • In fan forums, people often call it inconsistent writing, since Grievers are hyped as nearly always fatal, making Ben’s survival long enough to return feel unlikely or unexplained.

TL;DR: Ben got stung by a Griever while running the Maze in broad daylight, off‑screen; the movie only shows him afterward, infected and dangerous, which leads to his banishment.

Information gathered from public forums or data available on the internet and portrayed here.