IDÉES POUR RYZOM

while such a thing would on the surface be nice, it wouldn't be nice for people coming to an area after you're done grinding on those najabs for example.
Say after you've killed them 10 times they now take an hour to spawn instead of 20 seconds. You've gained a level, which is what you're after, but the next person coming along can't find any.

Similar with kitins. Would be very easy to kill enough of them to trigger that invasion, then port out. Do that in a major digging area and you're preventing others from digging...

Such complications are probably among the reasons this hasn't been (fully) implemented.

There would not be a "major dig area", because mats would also be constantly on the move. Nor would there be a "next person coming along" expecting a najab spawn there, since that too is a product of the current system where we know najabs to reliably appear in a specific location.

If you learn what something hunts, and the types of environments it likes, find the things that it hunts in those environments. There is a very high likelihood that you'll find the predators that you are looking for. If you don't know, what is it that you do in this game? Ahh yes, ask someone else! This will get people out and exploring more of the world, instead of just lining up in Void waiting for the groups ahead of you to finish the "grind" mob spawns so you can have your turn.

For the Kitin "uprising", yeah, that's a real threat. That's why you can see them from a distance. If you see a group of Kitin in the distance, don't go there. People dig in the Kitin Lair, and aggro is constantly harassing them. There are Kitin patrols in PR constantly harassing diggers there too. There are also aggressive named creatures that patrol back and forth through digging spots. Sometimes, some seasons, what you want to dig is safe, and then other seasons, a bunch of aggro is sleeping on top of it. Sometimes aggro sleeps on your target during every season. Somehow, despite all of that, digging still miraculously happens, believe it or not. People whine about those things, but the digging still gets done.

I would expect to see Kitin soldier groups in areas where Kitins had been killed often, perhaps even escorting the Kitins that had been dying. As the kitins there stop dying, the guards and patrols would gradually disappear.

But more realistically, if the Kitins above ground behaved with purpose like those in the Lair, there wouldn't be static "spawn groups" of Kitins just sitting anywhere milling about, like today and like in every other boring MMO to date. They would be performing their duties for the rest of their particular colony. Workers would use a different route instead of continuing through the dangerous spots, and soldiers would escort them and set up "checkpoints" (ie: come here to die please, homins!).

And in Ryzom, since things work best based on seasons (4.5 RL days), that is the most logical method to implement such pattern changes. You kill Najabs extensively that season, the next season the spawns will be diminished. Continue killing them season after season, and they won't be there for a while. Find where else they live.

What happens with all of this is you learn to adapt.
"Are you smarter than a level 5 Kitin?"