Originally Posted by Wisdom 
You have the option of collecting background items. But there isn't a visual cue (Edit: apparently there is a visible cue on lower difficulties, I just didn't play on that level) so you literally have to scan your mouse back and forth hoping it lights up as a collectible.
Hero missions are dull. Adding visual clues take away the little they have as it allows players to run for it.
Places/containers to search are usually the same, they might be empty though.