One curse I've had while playing and in particular while GMing, is that one group of players I have is stuck in the mindset that things are laid out, one after another, in linear fashion for them to go through. So, if for example, I make special mention of some critters out of place and behaving oddly, and then other relations like seemingly domestic versions of those critters in another town. Most people get the idea and realise there's something to investigate, something else going on behind the scenes. This one group, however, after all the setup, asks 'So where's the main monster lair?' of one of the NPCs. Totally stuck on this go kill boss monster get reward train and seemingly unable to grasp that he can take any action, he's not limited to north, east, south, west, open treasure chest, grab loot, etc.
Do any of you have tips on how to jar these players into actually playing and pretending they're in the situation?