In the game I was playing, the AI was doing some odd things. We've been making a point of not destroying warp gates when we can, but the AI has started doing something I haven't seen before. It's re-inforcing warp gates a lot. Like a HUUGE amount. In the screenshot I have attached, the system has been at alert for maybe an hour, and it has gone up to 1100 ships. Of those 1100, around 950 of them are centered around the warp gate. That happened in other systems we were attacking. Even systems without command centers, they would constantly spawn huge (100+ ships at a time) groups of ships at the warp gate, and would keep doing this every few minutes until a) All guard posts in the system are destroyed and we construct a command station, or b) we destroy the warp gate.
I'm not sure if this is intended behavior or not though, since I haven't been playing that long. I just haven't seen this kind of obsessive re-inforcing of one specific point, I always expected it to be spread out around all of the guard posts. The AI doesn't re-inforce any other points in a system once the AI loses control of it, just the warp gate.