Hi, I'm not sure what I'm going to describe comes from your mod that but just reporting in case it can help/make you aware that there is a potential bug. I also have a question regarding the AI.

So I have Rampant with default settings and some other biter mods installed (but I don't think they conflict).
I can survive regular attacks but every once in a while (about every 5 hours), super huge attacks start happening everywhere on the map with 5x more biters than usual and a continuous flow of them keep spawning, it is actually impossible to hold them even with ridiculous amounts of turrets.

However, if I reload the game shortly before or during the attack, biter spawning will go down to the normal rate and the attacks will shortly stop. Fortunately for me this makes an easy workaround for me to survive and continue playing, but also probably means something is bugged in your mod related to the AI saving its state.

Can you confirm this behavior (Huge but very rare attacks everywhere on the map) is actually a feature of your mod and explain me how I can tone it down without reducing the other aspects of the mod ?

Without a save, I will have trouble telling you if the mod is bugged during a save.

Depending on what state the AI goes into it may be spawning extra squads that appear to be a large attack.

What is your evolution at?

Turning off the Raid AI state may be useful to you, this will also have the side affect of reducing nests attacking from outside your pollution cloud. Otherwise I would recommend turning the difficulty scaling down to something like 0.4 in the map mod settings.

Well my save has 60+ mods which all have old specific versions, some of them being modified by me so it will not be that easy to share. Evolution is around 0.4. I have decreased manually a few times from 0.4 to 0.3 using "Change map settings" mod.

To be clear I don't expect you to fix this bug in particular because it is not annoying in my case, and very hard to reproduce (happens every 5 hours ..). Just wanted to hint that there might be something bugged regarding saving/reloading the AI state shortly before it was planning an attack. Maybe also the AI state evolves randomly which might explain why it happens differently after reloading.

Thanks for the setting, I'll try this and see if it decreases these attacks !