I started on a death world with a very big starting area.

At first enemies were out of pollution range so I was able to set up a factory and some defenses.

Once pollution reached the nearest nests I expected the biters to start attacking but they didn't. However they did start migrating towards my factory.
Then the new nests started sending attack waves. Many attack waves. Survival was tough and I really felt like they were trying to find the weak points in my defences.

Then suddenly, they stopped.

Now it's been a few (in-game) weeks and not a single bite has approached the factory. In the lull I've bolstered my defences and my industry, pollution is greater than ever, but still no attacks.

Is this expected behavior? Are they staying back because too many have died? Are they building up a massive attack force? Or did they just forget about me?

Without a save, I couldn't tell you.

Sorry I'm not familiar with this site. What is the best way to get you my save?

if it is a smallish size >15MB you could just use the forums under the homepage link on the information tab.

I posted in the forums, but I believe the message needs to be approved by a moderator as I haven't posted much. I'll write here, when it is up.

Sorry for the double-post, but the post on the forums is up.

(I'm gonna keep multi-posting, since this is my question thread :P)

As an update, I did find that if I poke them -hard- (destroyed dozens of spawners) I did get them to send a single attack. It was up to par on their evolution and almost broke through my defenses but they didn't attack again.

Thanks for the report, this should be fixed in the latest

I know this is an extremely long time ago, I had to step away from Factorio for a while, but I came back and test this out and I am happy to report that it is absolutely 200% fixed.

And now my Fort is a smoldering pile of rubble XD It was truly glorious.

I guess they had built up so many units they weren't sending and I had really laxed on my defenses from the lack of attacks. So I was not ready for the -flood- that followed :P

Thank you for fixing this!

(PS: Wish I could post pictures here, it was really Starship Troopers level of apocalypse lol)