敌人
敌对生物就是想要来干（危害）玩家的生物。敌对生物分为三种：食人虫，喷吐虫和沙虫。每种敌对生物都有三个成长阶段。
生物
食人虫
食人虫是两种主要的敌人之一。它们是外星世界的原住民，不会与喷吐虫和沙虫打架。食人虫是节肢动物，生活在虫巢中。它们有三种尺寸：小，中，大。在自由模式开局时，只会生成小的。但是随着污染的增加，它们的等级会提升。这与 进化有关系。 食人虫会被污染所吸引与激怒，因此它们会试图摧毁污染源。它们在看到玩家,防御塔以及物流机器人时，会转而攻击他们。 食人虫会给玩家造成身体伤害。
| 图片 | 名字 | 资料 |
|---|---|---|
| File:SmallBiter-anim.gif | 小型食人虫 | 最弱的食人虫，能被手枪轻松击杀。
|
| File:MediumBiter-anim.gif | 中型食人虫 | 比小型食人虫更肉也更慢。它们可能造成一些问题，有时它们甚至可以击杀弱小的玩家。
防御:
|
| File:BigBiter-anim.gif | 大型食人虫 | 很肉, 几乎对枪击无敌。他们几乎能直接破墙并攻击其后的东西。
防御:
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战斗
食人虫是对玩家工厂最常见的威胁。虽然他们的每次攻击都足以摧毁不设防的工厂，但大多数玩家能够在于小型食人虫的战斗中占据上风。它们也能被一定数量的防御塔阻挡。
污染会引起食人虫攻击，高污染工厂会更早地受到攻击。一旦污染范围达到了虫巢，玩家就能预见食人虫就会在很短的时间内出现。虫群会致力于摧毁污染源。但当遇见更有诱惑力的目标（玩家与防御塔）时，它们也会改变进攻计划。食人虫也有在防御圈上趁虚而入的能力。这一特性能部分用于控制食人虫的路径，使得防御塔有更长的攻击时间，但这个陷阱需要"诱饵"。 食人虫们不总会掉到圈套里。一些“聪明的”虫子会看透陷阱，并直接攻击你的墙。这会使你的陷阱失效，也使得食人虫们更加危险。
喷吐虫
除了它们的外表，喷吐虫与食人虫很像。它们唯一的不同点是攻击地点不等。他们会向所有对手(例如：玩家)喷吐不可闪避与被转移目标的酸球。通常，建筑物(例如炮塔与护甲)的酸液防御能力要比物理防御能力低得多，因此喷吐虫造成的平均伤害会比食人虫高。除了它们的血量与防御不同，它们的大小与行为与对应的食人虫很像。
| 图片 | 名字 | 信息 |
|---|---|---|
| File:SmallSpitter.png | 小型喷吐虫 | 最弱的喷吐虫。能在其射程外轻松被任何一种武器轻松击杀。
|
| File:MediumSpitter.png | 中型喷吐虫 | 比小喷吐虫更慢也更肉了。它们可能造成一些问题，有时它们甚至可以击杀弱小的玩家。远程攻击，使得它对防御塔十分危险。
防御:
|
| File:BigSpitter.png | 大型喷吐虫 | 它是最大的喷吐虫，也能造成最大的伤害。远程攻击使得它对防御塔以及玩家造成了巨大的威胁。
防御:
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沙虫
The Worms are natural allies of Biters and Spitters and will attack you if you get close enough. They act like static turrets and will not follow you, but due to much greater range, in comparison to other enemies, will be able to inflict damage with out leaving the nest. However, their static nature does render them more vulnerable to certain attacks.
Like any other enemy, worms come in 3 sizes, their power increasing with size. Unlike Biters and Spitters, Big and Medium Worms can be created directly after start of a new game, and will not always spawn near spawners. Their appearance is not dependent on time. (see http://www.factorioforums.com/forum/viewtopic.php?f=23&t=6454)
Worms deal acid damage.
| Picture | Name | Description |
|---|---|---|
| File:SmallWorm.png | Small Worm | A weak worm. Still not easy to kill though.
|
| File:MediumWorm.png | Medium Worm | Medium worms are very dangerous to even more advanced players. They should be handled with care.
Resistances:
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| File:BigWorm.png | Big Worm | Big worms are the most powerful enemy in factorio. They deal a high damage and are almost immune to common gunfire of any sort.
Resistances:
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| Picture | Name |
|---|---|
 |
Worm's animation |
Spawners
| Picture | Name |
|---|---|
| File:Nest.gif | Biter's Nest |
| File:Spitternest.gif | Spitter's Nest |
Evolution
The game evolution factor is a global variable that determines what kind of biters will be spawned. You can check the variable in the dev console:
game.player.print(game.evolutionfactor)
It goes from 0 (not evolved at all) to 1 (maximal evolution). At the moment the evolution factor can only increase. This evolution factor is increased by three kinds of events:
- The passage of time very slightly increases the evolution factor.
- The production of pollution (globally) increases the evolution factor.
- Destroying the enemy spawners significantly increases the evolution factor.
All these values are set in mapsettings. There they can also be changed / modded.
Current (0.9.1) default settings are:
-- percentual increase in the evolution factor for 60 ticks (game second) game.player.print(game.mapsettings.enemy_evolution.time_factor
0.000008
-- percentual increase in the evolution factor for 1000 Pollution Units game.player.print(game.mapsettings.enemy_evolution.pollution_factor)
0.00003
-- percentual increase in the evolution factor for every destroyed enemy spawner game.player.print(game.mapsettings.enemy_evolution.destroy_factor)
0.005
The percentages are applied on the base of (1 - current_evolution_factor). So for instance destroying the enemy spawner in the beginning of the game results in increase of evolution factor by 0.005 (half a percent) while doing this when the evolution factor is 0.5 the increase is only 0.0025 (quarter a percent).
As of 0.9.1 the biter spawning is done probabilistically based on the current evolution. Lets imagine a wheel - the "spawning wheel". We will be slicing that wheel as a cake. Small biters take the first 0.3 part of the wheel, medium ones the middle 0.3 part and big biters take the last 0.4. When a biter is about to be spawned the random point on the wheel is selected limited by the current evolution. So in theory while the evolution is below 0.3 there should be only small biters, then slowly medium ones will enter and in the end the big ones. The composition of the biter animation in the end should be 0.3-0.3-0.4. There is one more factor called the spawn_shift - this is a mechanism when the further away from the starting location the more the "rolling of the wheel" is shifted towards one. That means that if the shift is 0.2 for instance that at the time when evolution factor is 0.25 the result for spawning is actually 0.2 + 0.25 = 0.45 and a medium biter might be spawned.
Besides choosing what kind of biter will be spawned the evolution also influences the spawning interval. As of 0.9.1 this interval (spawning_cooldown in the enemy-spawner definition) is interpolated between 360 (0 evolution) and 150 (1 evolution) ticks.
All the values for the spawner (distribution of the biters based on evolution, the spawning shift, spawning_cooldown, etc.) can be modded from the data.
Expansions
Sometimes a small group of biters will leave their base to create a new base. This group will search for a suitable spot that's about 3 chunks away from existing biter bases and 3 chunks away from any of your buildings. Once they have found a suitable spot the group of biters dies and forms a new base. This new base will first be very small (about one spawner and a few worms) but will get some additional spawners within a small area as time passes. This base-wide expansion is somehow limited (the blog says something about 7, but that doesn't seem to match reality in some cases).