Antlion

Antlions (generally referred to as biotics by Combine forces) are a species of insect-like aliens that have arrived on Earth, from Xen, through the Portal Storms. They live in colonies with an intricate caste system, similar to Earthly ants, bees and termites. Antlion husbandry was once a common Vortigaunt practice and many valuable substances can be harvested from the various antlion castes.

Antlions dwell in underground colonies, made up of complex tunnels either carved out by workers’ acidic sprays (see below), or made of up already existing caverns. Antlions are very sensitive to vibrations in the earth and prefer to make their nests bellow soft earth or sand, which allow them to detect the movement of the creatures above. Structures similar to large termite-mounds can often be seen on the surface of a colony. These provide ventilation for the colony.

The inside of a colony contains many tunnels and chambers for various purposes. The larvae are housed in an expansive chamber that is surrounded by many chambers containing concentrated numbers of grubs. As well as the walls of the tunnels themselves, non-sticky webs are used to create walkways, storage areas, perches for grubs and to seal off tunnels.

Castes

Larva

Antlions start their life as larvae in small, honeycomb-like structures housed in a large chamber. They are tended to by the other antlions have their own dedicated protector; the antlion guardian. This is a necessary precaution, as not only are the larva the most delicate form of antlions, but they are also highly sought after by Vortigaunts, for an extract which allows full submersion in the Vortessence.

Grub

The next stage of development for antlions is the grub form. Grubs are small, docile creatures that spend their time passively clinging to available surfaces and feeding. Grubs are spread out through the whole of a colony, even to the very outskirts, but have much more concentrated numbers around the larval chambers. They are tended-to and fed by workers, often with human-meat.

When frightened grubs will chirp in alarm but make no move to defend themselves. If one squashes a grub (an easy feat to accomplish) a yellow pellet is excreted. This pellet has powerful healing properties and is particularly useful for hive robbers who have attained antlion-related injuries.

Common Antlion

Known generally just as antlions, these are the most well-known and seen caste, because they are the ones that venture above-ground the most. They can sense vibrations through soil and sand, and will viciously attack all trespassers. They are especially violent during the spawning season. Once a victim has been killed, they will return the body to the hive so that it can be used to feed the other antlion castes, including the grubs.

These antlions possess the ability to jump large distances using their powerful leg-muscles and small wings, allowing them to easily reach prey that is some distance away or that is on higher ground. It is possible that these wings allow partial- or full-flight in the lower-gravity environment of Xen. These antlions generally attack using their large front legs, which taper down into sharp claws and although they are comparatively weak, a small group can easily overwhelm even a heavily armed individual.

Worker

Antlion workers (also known as acidlions) rarely venture outside of the colony. As one would expect, they build, maintain and run the colony. A worker’s most unique feature is its long-range, toxic acid spray, which is used mainly for the carving out of tunnels for the colony but can also be used to attack interlopers. At close-range workers can also attack with their front claws, similar to the common antlions. They also share their brethren’s jumping abilities. Upon death workers will usually explode in a spray of acid, unless they die of drowning.

Guard

The guards (Myrmidonts) are the large, powerful, heavily-armoured defenders of the colony. They typically arrive when large numbers of the common antlions have been killed or when the colony itself has been tampered with. They will attack single-mindedly and fiercely all threats, that is, any living creature in the vicinity that isn’t an antlion.

Their main method of attack is a lunging head butt that will kill most targets on impact. At long range they can use their heat butt to launch heavy objects at a target with deadly accuracy. Guards can control other antlions using pheromones, allowing it to coordinate attacks. Killing a guard is no easy task; they can resist several blasts from high explosives or direct hits with an energy pellet.

Guardian

A guardian is a special form of guard whose sole duty is to protect the larvae of the colony. They are distinct from ordinary guards by their green body with luminous yellow sections.

They alls excrete deadly poisons, making their head butts even more deadly. They will hunt down any intruder who dares approach the larvae, and will even follow one out of the nest again. If a guardian is killed, the larval extract will be ruined. What causes this is unknown, but it makes life even more difficult for those who wish to posses the extract.

King

Little is known about the patriarch of the antlion colony other than his gargantuan size. A man could be crushed between the folds of a king’s skin and it could easily crush a strider. The king is believed to be the principle breeder of the colony, but whether a queen exists or whether it mates with the other, comparatively dwarfish, members of the colony in unknown.

Counteracting antlions

Defence against a nearby antlion nest is difficult as they are almost impossible to rout. The best one can hope for is to try and stop them spreading. Containment is really the only solution and for this purpose, large machines, dubbed restrictors by the Combine or thumpers by the rebels, that pound the ground relentlessly have been developed.

Antlions find the massive vibrations caused by these machines intimidating and refuse to approach them or tunnel beneath them. These must be maintained non-stop because antlions are always eager to spread their reach and a single weak-point will cause antlions to pour through the breach. It should be noted that guards generally seem to ignore thumpers, not being bothered by their presence in the least.