When will the AI use its settlers?

They have two settlers (had one for quite a while now) and are so far focusing mainly on military strength. What should I expect from them - are they waiting for something before settling? Is this settler stockpiling a normal thing? I usually don't team with an AI so I haven't observed this before.

Update:

So they stocked up 7 warriors (notice how they are the only ones on the island besides a city state - you may not be able to see it completely but I later explored it) and got a 3rd settler. That 3rd settler they finally settled. They are still stockpiling 2 settlers and are way overcompensating military might. I am still baffled by this AI.

Additional info:

It is a mod game with [BNW] Mass Effect Civilizations enabled. There is no mention of any AI tweaks so my understanding is that even though it is a modded civilization, it is still using vanilla AI. The AI in question is the Ranchi Civilization.

Solution 1:

I'm not sure if this is Comment or Answer worthy as it's mostly speculation at my own experiences but here it goes (The way I see it is this might not answer directly or completely but it may help give-way to other answers and/or possibilities):

When playing I've noticed that an AI opponent will do one of three things with a settler:

• 1) Send it immediately to its destination.
• 2) Wait for a military unit to escort it. If it doesn't have one it will make one.
• 3) Wait for a position to open up then move it.

With 3) the only time I've noticed this was when there was one good opening in the entire area for a city. I had a unit nearby and the AI started moving their settler there. The second I blocked the exact tile they wanted (with my military unit; we weren't at war) they stopped their settler and moved him back to their capital.

This could have been a coincidence but I feel like it was too exact to be one. Additionally, I believe that difficulty-level affects their choices, I know at lower levels the AI will quite commonly do 1).

Your case:

Obviously looking at my list none of them seem to apply. Is this a modded-civilization? The colors don't look familiar, there's no guarantee but it might be a bug or something about the civilizations's trait-setup that could be making them act this way.