"Monster closets". The term refers to the way in which the game would spawn enemies if you reached a set point. Thankfully id have scrapped such design philosophy.
Speaking with 1up, Rage lead designer Matt Hooper explained that enemies will be "doing whatever they're supposed to be doing. If they're supposed to be defending against you coming there, they'll be doing that. If they're just tinkering or having a conversation they'll do that."
Blimey, real AI? Thank goodness.