I havent seen Harpies raiding faction controlled systems (no fleets moving to of from systems they haven't started in) ever since a major AI rebalance where Pirate and Harpy raids were disabled

Played easily over 50 games since then but no raids that I have seen

But today I ran into this sight where they seems to have attacked a system belonging to AI controlled Yoral:


Has anyone seen Harpies attacking systems like that in recent past?
Is it maybe a bug or a constellation of settings that has triggered it (I have played around with initial galaxy generation Raiding intensity setting but didnt seem to effect the behavior before)

On the above particular game I am at turn 249 and havent been attacked by Harpies myself

Seen two occurrences explaining colony and nest sharing the system:
1) harpy reinforcements were underway when the system was cleared and claimed;
2) fleet containing colony ship or outpost arrives at a harpy system, and notifications to fight harpies and claim the system appear simultaneously. Harpies do not attack colony established this way, even if you lose/flee the fight.
This is not considering the Yorals somehow acquired Harpy repellent tech.
So no, I don't think the raids are enabled.

PrivateHudson wrote:1) harpy reinforcements were underway when the system was cleared and claimed;

I've had this happen to me. The harpy raid message then appears.

PrivateHudson wrote:This is not considering the Yorals somehow acquired Harpy repellent tech.

Yeah, this can happen.

I had the nasty surprise sometimes when sending scout ships to AI empire-controlled systems that it was full of harpies. I've also seen sometimes an AI empire send a colony ship to a harpy-infested system and just successfully build a colony here.

Those are rather rare occurrences, but they do happen sometimes and I've generally interpreted them as the AI empire having acquired the tech from the Herald. After all, AI empires do research the anomaly tech, as I've quite often acquired it (at least partially) by conquering systems.