Quote Originally Posted by Unoriginal View Post
An Imp sitting in a fire will likely be pretty noticeable, even if they're invisible.

Invisible spies don't want to stand in the middle of something that can reveal the outline of their bodies.
Yeah. It's amazing how people seem to believe that being invisible is more like being immaterial except you can't pass through solid objects.

You're still there, your wings (if flying) still beat, your breathing still disturbs air, your scent is still there. If you fly through fog, you leave eddies. If you walk through mud, you still leave tracks. The only thing invisibility does is defeat direct sight. Anything else is more of the "it's magic, so it gets special hidden features" favoritism so common to D&D discussions.