Aliens attacking trade routes?

[stepic]

Do they always attack trade routes? If not, under what circumstances they do? I have a city founded next to an alien nest and a trade route going to that city, but not through hexes adjacent to the nest, and they destroyed the trade route.

I suspect they might have done that because I aggroed them by having a city next to the nest. How do you tell a neutral alien from aggressive?

 

[Jimbo30]

I think 2 hexes sight is pretty much auto kill for them vs defenceless units. Any early (not sure about later) unit within 2 hexes of a nest will be attacked from my experience, so don't go exploring really deep until you have Purity 1. Otherwise they generally leave explorers and stronger military units (ie non rangers) alone from what I can see.

 

[Svetkavitsa]

If a green/orange/red alien ends its turn on your trade unit's route and your convoy/vessel moves through it, it will be destroyed.

If aliens are blue, trade convoys/vessels can freely move through them.

 

[joncnunn]

Also, there's a quest you can do that will give your trade route units immunity from aliens if you pick the right decision. (Reverse the polarity)

 

[Magma_Dragoon]

I've had routes across the ocean full of green aliens for about 75 turns now and nothing has happened to any of them so far.

 

[Leuthesius]

Reverse the polarity apparently bugged in my game.... Aliens STILL attacking my trade routes despite that.

edit:

My bad. "Automatic Gratification" is the quest needed for this. It hadn't kicked off yet.

edit:

Still had an alien hit one of my trade ships...