Unfortunately, they're not as smart as they could be, and they seem to have a particular problem with stairs. If you're a floor above them and tell them to follow you, they'll just stand underneath your position and bleat plaintively until you specifically order them to walk over and climb the stairs. They're also completely ignorant of hazards, so if you're not careful, they'll happily saunter into open flames or electrified floors like brainless lemmings.
Despite this irksome flaw, Exit will keep you hooked. This is partly because of the frustration from all the many near-misses you'll experience in each stage, but also because each disaster area is cleverly designed and fiendishly challenging to figure out. And once you've finished its 100 stages - which takes a while - you can download even more levels for free.