Antlion Grub

The Antlion Grub is an Antlion larvae, found in the first two chapters of Half-Life 2: Episode 2. The grubs are maggot-like creatures, emitting a high chirping call and bioluminescence similar to that of a firefly. They are found in Antlion nests hanging on any surface available. They are extremely fragile, and can be killed by merely touching them. These grubs seem to be carnivorous, as hinted by many dead bodies and skeletons near scattered near them. Grubs exude a filmy thread, similar to that of a silkworm but on a much larger scale. In the White Forest Mines, this web often blocks whole passageways. Every Antlion in the nest will protect its grubs fiercely.

Grubs contain a yellow substance with healing properties. Killing the grub releases this fluid. Within the game, how much the substance heals is dependent upon the players' current health level.

Achievement
Possibly the hardest achievement in Episode 2 can be unlocked by killing all 333 Antlion grubs in the game. Another can be achieved by breaking open all 9 of the stashes of supplies found trapped in the grubs' webs.

Behind the scenes

 * The Antlion Grub was originally to appear in the coast levels of Half-Life 2 in the Antlion caves. The original grub model and the Antlion caves map can be found in the files leaked in 2003.
 * It was originally intended that killing Grubs summoned Antlions to attack the player. This was dropped after the developers noted that players became afraid of bursting the grubs for health, thus making the underground sections of Episode 2 too hard and discouraging attempts at unlocking the achievement.