If you clear an area with melee weapon oh well but if you try to clear via shooting they spawn right behind you in a matter of seconds and quite close, once I actually turned real fast and saw one spawning in front of me, lol.
Yes this game has great potential even to become mmo but right now this is one uber ridiculous game...
No when they spawn meter from you and in front of your eyes it does not make sense! And no when you empty a mag on all of it's limbs and he acts like nothing happened it does not make sense!
Another thing, even when I clear a house with melee weapon or silenced gun they occasionally spawn in the house! that does not make sense!