Enemies

Enemies are creatures that want to harm the player. They normally come from spawners and begin on the enemy force. There are three types of enemies: Biters, Spitters and Worms. Each of these types comes in three stages of growth and thus strength.

Achievements

Main article: Achievements

Enemies are directly connected to the following achievements:

It stinks and they don't like it

Trigger an alien attack by pollution.

Steamrolled

Destroy 10 spawners by impact.

Creatures

Biters

Biters are one of two main antagonists in the game. They are the native inhabitants of the extraterrestrial world and commonly live peacefully with worms and spitters. Biters are arthropods living in organic nests. They come in four sizes: small, medium, big and behemoth. In the beginning of each freeplay game there will only be the small ones, with increasing pollution they will become bigger, related to the enemy's evolution. Biters are attracted by and enraged by pollution and will attempt to destroy its sources. They prefer to attack the player character, turrets and logistic robots and will stop searching for pollution if they can see and attack any of those. Biters deal physical damage.

Picture	Name	Info
File:SmallBiter-anim.gif	Small Biter	Weakest of biters, can be easily killed with a pistol. Health: 15 Damage: 6
File:MediumBiter-anim.gif	Medium Biter	Stronger and slower than the small biter. Can pose a problem for and even kill weaker players. Health: 75 Damage: 15 Resistances: Explosion: 0/10% Fire: 0/-50% Physical: 4/0%
File:BigBiter-anim.gif	Big Biter	Very resistant and dangerous, nearly immune to gunfire. Can attack through walls and hit objects directly behind them. Health: 375 Damage: 30 Resistances: Explosion: 0/10% Physical: 8/0%
File:BehemothBiter-anim.gif	Behemoth Biter	Very resistant and dangerous, nearly immune to gunfire. Can attack through walls and hit objects directly behind them. Health: 5000 Damage: 100 Resistances: Explosion: 10/20% Physical: 8/20%

Combat

The biter class enemy will likely be the most common threat to a player's factory. While any attack can catch an undefended factory off guard, most players will be able to handle attacks from small biters with relative ease. Medium biters often pose a much greater threat though due to their heavy armor, not present on small biters. Big biters are another step in this direction and can come as another nasty shock to any player not familiar with their world's evolution level. Behemoth biters are a huge threat to any factory and serve as the Player's prime incentive to avoid excess pollution. However, Biters of any size can be managed by static defense, though some of the larger waves can be overwhelming.

Biters come fairly early to attack a factory that produces large amounts of pollution, as pollution will attract an attack. Once the pollution cloud reaches a nest, the player can expect biters to be showing up shortly. The attack group will be focused on destroying the source of the pollution, but will change targets as soon as one appears of higher priority, typically by level of pollution, though they target the player or static defense first and foremost. Biters also have the ability to find their way around a defense, to a degree. This can be used to partially control the movement of the biters allowing turrets longer to damage them, but requires the "bait" of this trap be left open. Biters aren't always willing to fall for the bait. Some biters will choose the most direct route and will attack the walls of the trap regardless making them less predictable and more dangerous.

Spitters

Spitters are much like Biters. The only difference, besides their appearance, is that they only have got a ranged attack. They spit at any opponents (e.g. players) with an acid projectile that can neither be dodged nor deal damage to anything else than the original target. Commonly the acid resistance of any buildings (like a turret) and armor is much less than its physical resistance. Because of this Spitters deal more average damage than Biters. Their behavior and sizes are very similar to the Biter ones, except their health and resistances.

Picture	Name	Info
File:SmallSpitter.png	Small Spitter	Weakest of spitters. Easy to kill with any weapon, but attacks at range. Health: 10 Damage: 10
File:MediumSpitter.jpg	Medium Spitter	Stronger and slower than the smaller version. Can pose a problem for and even kill weaker players. Attacks at range, making it dangerous for turrets. Health: 50 Damage: 20 Resistances: Explosion: 0/15%
File:BigSpitter.png	Big Spitter	An even bulkier spitter and so can take more damage. Attacks at range, making it dangerous for turrets and the player. Health: 200 Damage: 30 Resistances: Explosion: 0/30%
File:BehemothSpitter.jpg	Behemoth Spitter	The bulkiest of the spitters and so can take even more damage. Attacks at range, making it dangerous for turrets and the player. Health: 2000 Damage: 50 Resistances: Explosion: 0/35%

Worms

The Worms are natural allies of Biters and Spitters and will attack the player if they get close enough. They act like static turrets and will not follow you, they will instead use their much greater range, in comparison to other enemies, to inflict damage without 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, however their appearance frequency can be modified by distance from the initial player spawn point, with greater distance yielding bigger/more worms.

Picture	Name	Description
File:SmallWorm.png	Small Worm	A weak worm. Still not easy to kill though. Health: 200 Damage: 10 (acid)
File:MediumWorm.png	Medium Worm	Medium worms are very dangerous to even more advanced players. They should be handled with care. Health: 350 Damage: 30 (acid) Resistances: Explosion: 5/15% Physical: 4/0%
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. Health: 500 Damage: 60 (acid) Resistances: Explosion: 10/30% Physical: 8/0%

Picture	Name
	Worm's animation

Big Worms Now Show Up In Early Game

Spawners

Picture	Name
File:Biternest-anim.gif	Biter's Nest	Health: 350 Resistances: Explosion: 5/15% Physical: 2/0%
File:Spitternest.gif	Spitter's Nest	Health: 350 Resistances: Explosion: 5/15% Physical: 2/0%

Enemies are creatures that want to harm the player. They normally come from spawners and begin on the enemy force. There are three types of enemies: Biters, Spitters and Worms. Each of these types comes in three stages of growth and thus strength.

Achievements

Main article: Achievements

Enemies are directly connected to the following achievements:

It stinks and they don't like it

Trigger an alien attack by pollution.

Steamrolled

Destroy 10 spawners by impact.

Creatures

Biters

Biters are one of two main antagonists in the game. They are the native inhabitants of the extraterrestrial world and commonly live peacefully with worms and spitters. Biters are arthropods living in organic nests. They come in four sizes: small, medium, big and behemoth. In the beginning of each freeplay game there will only be the small ones, with increasing pollution they will become bigger, related to the enemy's evolution. Biters are attracted by and enraged by pollution and will attempt to destroy its sources. They prefer to attack the player character, turrets and logistic robots and will stop searching for pollution if they can see and attack any of those. Biters deal physical damage.

Picture	Name	Info
File:SmallBiter-anim.gif	Small Biter	Weakest of biters, can be easily killed with a pistol. Health: 15 Damage: 6
File:MediumBiter-anim.gif	Medium Biter	Stronger and slower than the small biter. Can pose a problem for and even kill weaker players. Health: 75 Damage: 15 Resistances: Explosion: 0/10% Fire: 0/-50% Physical: 4/0%
File:BigBiter-anim.gif	Big Biter	Very resistant and dangerous, nearly immune to gunfire. Can attack through walls and hit objects directly behind them. Health: 375 Damage: 30 Resistances: Explosion: 0/10% Physical: 8/0%
File:BehemothBiter-anim.gif	Behemoth Biter	Very resistant and dangerous, nearly immune to gunfire. Can attack through walls and hit objects directly behind them. Health: 5000 Damage: 100 Resistances: Explosion: 10/20% Physical: 8/20%

Combat

The biter class enemy will likely be the most common threat to a player's factory. While any attack can catch an undefended factory off guard, most players will be able to handle attacks from small biters with relative ease. Medium biters often pose a much greater threat though due to their heavy armor, not present on small biters. Big biters are another step in this direction and can come as another nasty shock to any player not familiar with their world's evolution level. Behemoth biters are a huge threat to any factory and serve as the Player's prime incentive to avoid excess pollution. However, Biters of any size can be managed by static defense, though some of the larger waves can be overwhelming.

Biters come fairly early to attack a factory that produces large amounts of pollution, as pollution will attract an attack. Once the pollution cloud reaches a nest, the player can expect biters to be showing up shortly. The attack group will be focused on destroying the source of the pollution, but will change targets as soon as one appears of higher priority, typically by level of pollution, though they target the player or static defense first and foremost. Biters also have the ability to find their way around a defense, to a degree. This can be used to partially control the movement of the biters allowing turrets longer to damage them, but requires the "bait" of this trap be left open. Biters aren't always willing to fall for the bait. Some biters will choose the most direct route and will attack the walls of the trap regardless making them less predictable and more dangerous.

Spitters

Spitters are much like Biters. The only difference, besides their appearance, is that they only have got a ranged attack. They spit at any opponents (e.g. players) with an acid projectile that can neither be dodged nor deal damage to anything else than the original target. Commonly the acid resistance of any buildings (like a turret) and armor is much less than its physical resistance. Because of this Spitters deal more average damage than Biters. Their behavior and sizes are very similar to the Biter ones, except their health and resistances.

Picture	Name	Info
File:SmallSpitter.png	Small Spitter	Weakest of spitters. Easy to kill with any weapon, but attacks at range. Health: 10 Damage: 10
File:MediumSpitter.jpg	Medium Spitter	Stronger and slower than the smaller version. Can pose a problem for and even kill weaker players. Attacks at range, making it dangerous for turrets. Health: 50 Damage: 20 Resistances: Explosion: 0/15%
File:BigSpitter.png	Big Spitter	An even bulkier spitter and so can take more damage. Attacks at range, making it dangerous for turrets and the player. Health: 200 Damage: 30 Resistances: Explosion: 0/30%
File:BehemothSpitter.jpg	Behemoth Spitter	The bulkiest of the spitters and so can take even more damage. Attacks at range, making it dangerous for turrets and the player. Health: 2000 Damage: 50 Resistances: Explosion: 0/35%

Worms

The Worms are natural allies of Biters and Spitters and will attack the player if they get close enough. They act like static turrets and will not follow you, they will instead use their much greater range, in comparison to other enemies, to inflict damage without 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, however their appearance frequency can be modified by distance from the initial player spawn point, with greater distance yielding bigger/more worms.

Picture	Name	Description
File:SmallWorm.png	Small Worm	A weak worm. Still not easy to kill though. Health: 200 Damage: 10 (acid)
File:MediumWorm.png	Medium Worm	Medium worms are very dangerous to even more advanced players. They should be handled with care. Health: 350 Damage: 30 (acid) Resistances: Explosion: 5/15% Physical: 4/0%
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. Health: 500 Damage: 60 (acid) Resistances: Explosion: 10/30% Physical: 8/0%

Picture	Name
	Worm's animation

Big Worms Now Show Up In Early Game

Spawners

Picture	Name
File:Biternest-anim.gif	Biter's Nest	Health: 350 Resistances: Explosion: 5/15% Physical: 2/0%
File:Spitternest.gif	Spitter's Nest	Health: 350 Resistances: Explosion: 5/15% Physical: 2/0%

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).

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).