Zombie bears seem to be buggy. They kept running backward and doing this rubber-banding dance. Also, they kept glitching up the metal shelves in stores. Fortunately, I had just found a rifle.
I had one spawn when I was at a gun store and few minutes after killing it another one spawned. A little overkill for a level 14 character???
POIs seem to be overpopulated by zombies. And the owesome loot they're guarding (as MM said) is not there. I mean, I found the boxes but nothig worth the zombie ifested, landmine trapped regular house. Maybe I'm low level and no looting perks but then there shouldn't be so many sombies also. I was like level 5 when I explored this POI. There was like more than 20 zombies in there.