I've seen this in both of the games I've played so far. I'm at peace with an AI player and we have open borders. However, the moment one of my scouts enter one of their systems, they send me nervous diplomatic messages, and after about 5 rounds of that, they declare cold war. Meanwhile, their scouts are happily zooming through all my systems.

This seems pretty illogical. Shouldn't the AI recognize scouts for what they are and not get worried? Especially when they seem to think it's acceptable for them to send scouts into my systems.

It is a bit over the top, but you can geta around this by desigining a scout ship without a weapon module. It only sucks if you explore and trigger a trap event. The AI miss-using open borders like the unfallen and the scouts and whatnot getting through is also something that irritates me. 

Ozgwald wrote:

It is a bit over the top, but you can geta around this by desigining a scout ship without a weapon module. It only sucks if you explore and trigger a trap event. The AI miss-using open borders like the unfallen and the scouts and whatnot getting through is also something that irritates me. 

I'd suggest building a remote scouting variant and a "home" variant. That way you can still annihilate the occasional lone pirate who don't understanding the meaning of high tier weapons and armor. 

I think the ai should consider the type of ship instead of the amount of weapons.

Ah, this might explain why both Horation and Unfallen get mad at me ''amassing an army near their terretory''. My army being the the complete other side of the galaxy, maybe a scout ship explored near them.

Yeah, it's a bit nuts, especially when they lose their shit over a single (poorly-armed) scout vessel. It wouldn't be quite so aggravating if the roaming pirates weren't armed to the teeth themselves.