AI is hording it's waves by putting ships on it's own planets.

[Buttons840]

In my most recent game the AI has been sending waves to it's own planets (at least, I assume as much, because they aren't attacking me).  The warning say 100 ships to ? in 2:00.  Or something like that.

Now the AI is approaching a threat level of nearly 1000.  I've scouted nearby planets and haven't see a large number of ships nearby.  I wonder whats going on?

[Doddler]

That sounds like a raid engine.  If a system with a raid engine goes on alert (large fleet in an adjacent system or a command center in an adjacent system is destroyed), they'll send waves to that system every 3 minutes.  The ships SHOULD go after you (they might wait around for friends but they should eventually become aggressive), but I've had similar cases where ships that become threat aren't really interested in going anywhere.  It might be a bug, if you posted a save file someone might be able to figure out if those ships are behaving correctly.

[eRe4s3r]

The wave to ? indicates that only 1 AI has a raid connection to you via warpgate. Maybe no warpgate from AI2 borders to your worlds.

The 2 AI's have each their own raid path and if you cut off 1 ai from raiding into one of your planets these ships will be used for something similar to a cross planet raid, just way more dangerous.