Getting biters to attack

[SpeedDaemon]

I'm playing a game with the Bob's Enemies mod, and since it's a "mega train" game, I need several tens of thousands of alien artifact drops.

I have a farm built, and several mines dumping 20k+ pollution, but while the nearby biter bases produce hordes of biters and spitters, they mostly just mill around in their "staging" groups twiddling whatever appendages they have that pass for thumbs. Every once in a while they wander over by ones or twos, or maybe a small group. If you look at the pics below, you can see 7-8 groups of biters that look like they're ready to attack, but don't. The nests just make more groups. There also seems to be a lot of movement north-south between the biter bases/staging groups.

I've seen videos of similar setups where they attack by the hundreds almost constantly (which is what I need), so I'm wondering if there's something I'm doing/not doing that's causing problems.
I am throttling the mines to make the ore last longer (but compensating with more beacons). Maybe it's just a matter of MOAR POLLUTION?

Pics:
Map with pollution off and expansion chunks on:
http://theharms.org/misc/factorio-pics/ ... rm-map.png

Same, but with pollution showing:
http://theharms.org/misc/factorio-pics/ ... m-map2.png

Layout of the kill-zone and pollution generator. I left a gap in the wall to make sure they could path, and there are several radars, which usually really piss them off.
http://theharms.org/misc/factorio-pics/ ... r-farm.png

As far west as I can go without attracting attention. If I load up on shields and exoskeletons, it just gets denser as you go west.
http://theharms.org/misc/factorio-pics/ ... -horde.png

I'm running 0.12.20

mod list

0.101 Loading mod core 0.0.0 (data.lua)
0.103 Loading mod base 0.12.20 (data.lua)
0.145 Loading mod bobconfig 0.12.2 (data.lua)
0.172 Loading mod boblibrary 0.12.3 (data.lua)
0.203 Loading mod FARL 0.4.41 (data.lua)
0.233 Loading mod greenhouse 0.1.0 (data.lua)
0.263 Loading mod Landfill 2.1.7 (data.lua)
0.295 Loading mod RailTanker 1.1.2 (data.lua)
0.322 Loading mod RSORadar 0.0.1 (data.lua)
0.351 Loading mod TheFatController 0.3.15 (data.lua)
0.387 Loading mod upgrade-planner 1.1.7 (data.lua)
0.413 Loading mod VoidChestInstant 1.0.1 (data.lua)
0.444 Loading mod YARM 0.7.12 (data.lua)
0.474 Loading mod bobassembly 0.12.7 (data.lua)
0.512 Loading mod bobenemies 0.12.6 (data.lua)
0.543 Loading mod bobores 0.12.7 (data.lua)
0.580 Loading mod bobtech 0.12.4 (data.lua)
0.621 Loading mod bobplates 0.12.10 (data.lua)
0.664 Loading mod bobelectronics 0.12.6 (data.lua)
0.714 Loading mod boblogistics 0.12.7 (data.lua)
0.765 Loading mod bobmining 0.12.3 (data.lua)
0.819 Loading mod bobpower 0.12.6 (data.lua)
0.879 Loading mod bobwarfare 0.12.9 (data.lua)
0.951 Loading mod bobmodules 0.12.9 (data.lua)
1.018 Loading mod research-queue 1.2.2 (data.lua)
1.084 Loading mod bobconfig 0.12.2 (data-updates.lua)
1.168 Loading mod FARL 0.4.41 (data-updates.lua)
1.231 Loading mod bobassembly 0.12.7 (data-updates.lua)
1.296 Loading mod bobenemies 0.12.6 (data-updates.lua)
1.383 Loading mod bobores 0.12.7 (data-updates.lua)
1.446 Loading mod bobtech 0.12.4 (data-updates.lua)
1.508 Loading mod rso-mod 1.4.7 (data-updates.lua)
1.575 Loading mod bobplates 0.12.10 (data-updates.lua)
1.663 Loading mod bobelectronics 0.12.6 (data-updates.lua)
1.725 Loading mod boblogistics 0.12.7 (data-updates.lua)
1.791 Loading mod bobmining 0.12.3 (data-updates.lua)
1.873 Loading mod bobpower 0.12.6 (data-updates.lua)
1.937 Loading mod bobwarfare 0.12.9 (data-updates.lua)
2.017 Loading mod bobmodules 0.12.9 (data-updates.lua)
2.088 Loading mod bobelectronics 0.12.6 (data-final-fixes.lua)
2.162 Loading mod research-queue 1.2.2 (data-final-fixes.lua)

[ratchetfreak]

are you on peaceful mode? if so then they won't attack unless you attack them first

[Supercheese]

If you install the Natural Evolution Expansion mod, every time you place a rocket silo, it will trigger all nearby biters to simultaneously attack your base. Be prepared for the swarm!

Additionally, it will increase the default aggressiveness of biters.

Furthermore, the Natural Evolution Buildings module has a building that will regularly attract nearby biters.

[SpeedDaemon]

are you on peaceful mode? if so then they won't attack unless you attack them first

Don't think I've ever started on peaceful mode... I couldn't get the CLI command to print the value of game.peaceful_mode, and I would get attacked running near bases, but I did /c game.peaceful_mode = false just to make sure. No apparent change in behavior, though

[Dragonbeater89]

They may be preparing a mega attack to overwhelm those turrets. Other than that, I don't know. They do a similar thing on my game too, but they group once then attack. Try pissing them off with some low-level turrets so that they attack.

[BlakeMW]

Biters attack best when antagonized by the presence of the character. This is easily observed with "biter enclosures" where the biters will live peacefully when the character is far away, but when the character comes near they start throwing themselves against the enclosure turrets in droves. This appears to be a "defend the nest!" response triggered by character presence. This makes a biter enclosure a great way to slaughter biters and it's the most reliable way to generate attackers at a very rapid rate (certainly enough that when using laser turrets the turrets can draw hundreds of MW continuously)

The other thing which provokes them to attack is of course pollution but in that case they have their own internal logic on how long to mass for before attacking and spawners only absorb pollution and generate attackers at a limited rate (refer to https://wiki.factorio.com/index.php?tit ... ative_life - basically a spawner absorbs up to 20 pollution/s, and each enemy type has a pollution cost to spawn).

The Misanthrope mod makes biters much more aggressive even without antagonization.