Peaceful Mode — Alien Behavior Clarification

[Demetrius_Hudson]

Hello everyone,

I have a quick question regarding Peaceful Mode in the game settings.
If I enable this mode, does it mean that aliens won’t attack unless I initiate combat first?
And if I decide to destroy one of their nests, will they then retaliate and start attacking my base as usual, or will they remain passive?

Just want to make sure I fully understand how the mechanic works before starting a new save.
Thanks in advance for the clarification!

[Loewchen]

They will temporarily and locally attack if attacked, see https://wiki.factorio.com/Map_generator#Enemy.