I've been playing dalek mod on a single player world and the only hostile modded mob that will spawn is the daleks. No plastic men no clockwork robots. I am playing with some other mods so i dont know if that affects it. The mods im playing with are: Jei,baubles,astral sorcery, build craft,vein miner, travelers back pack, pams harvest craft and immersive engeneering. If anyone knows why this happens please tell me.