decrease of population problem

[Kref]

I am playing for ea pangaea. I have grouth 3 scale; I've casted carrion woods global enchantment. I constantle have about 100 corpses at my capital, so my capital's population decreases.
Is this a work of venom charm?
Also I have 68 harpies on patrol. I've two or three times caught harpie scouts of la pangaea; harpie scouts have +20 stealth.
I am suspicious that these corpses are the work of machaka's Ear of the lord, but such spies are also have +20 stealth, but I didn't still didn'r caught any of such spies. If this is a venom charm of machaka, how can machaka's spies avoid detection when harpies are caught?
There is also ma china in game, with imperial consort with +35 stealth, but it doesn't seem that china has interest in peace or war with me and machaka, as it doesn't have borders with me and i believe it doesn't have borders with machaka, especially long borders.