|Homeworld||Unknown (but inhabit Xen)|
|Average Height||~1m / ~3-4m|
Antlions are large insects (~1m high). They survive by burrowing themselves into the earth and hunting prey who wander into their territory unawares with their sharp claws. They are quick, and can also make long jumps by using their wings as support. They are an invasive species that breed incredibly quickly, and are very dangerous to humans.
Antlions are blind, but are sensitive to vibrations in the ground. This has been exploited by the Combine, who developed machines that repeatedly thump the ground, and thus cause Antlions a great degree of pain, keeping them away from valuable areas. Antlions are also highly susceptible to pheromones, which are secreted from the bodies of the Antlion Guards in order to attract and control their smaller brethren. Antlion Guards protect colonies and spearhead the creation of new ones, and are very big, possessing power comparable to that of a rhinoceros.
When done properly, one can surgically remove a pheromone gland from a dead Antlion Guard and use it to command and control any nearby Antlions, as seen when Gordon Freeman assaults Nova Prospekt. This does not have an effect on other Antlion Guards, however.
Antlion larvae secrete many valuable compounds, and were once bred by Vortigaunts, perhaps indicating that they originate from the same home world.
Antlion Workers are, as implied, the virtual backbone of an antlion nest. Due to their largely non-combative nature, they aren't plated with the natural armor of normal antlions, and instead look more bulbous and pale. They are capable of spitting an acidic and poisonous substance that, while used for carving away at rock, can be used as a defense mechanism. Upon death, Antlion Workers will explode into a small cloud of this substance, leaving behind only some legs and their head. Firearms and ranged weapons are thus suggested in dealing with them.