Giant ant

Giant ants are a low-level hostile creature commonly found in Fallout games.

Background
 These mutated arthropods, of order Hymenoptera, family Formicidae, and genus Camponotus (commonly called carpenter ants) were exposed to large levels of radiation. However, what really caused this rapid evolution and adaptation to the wasteland, creating what is known as a giant ant ("big fucking ant" to some) was exposure to Force Evolutionary Virus lingering in the fallout. Fallout Bible 1 Fallout Bible 0: "3. Are the radscorpions a product of the FEV virus? When you talk to the doctor, Razlo, in Shady Sands, he tells you that they were once American Emperor Scorpions but that he has no idea how they mutated because radiation alone couldn't have done it. For that matter, what about all of the other creatures of the wasteland? Which ones have been mutated by FEV and which ones haven't? Maybe in the bestiary each creature could have a stat that shows it's level of FEV infection." "Answer: Mantises. Most species of rats. Gecko lizards. Brahmin Scorpions Ants Various varieties of plants, including the Venus Flytrap. Rumor has it some dogs were affected, but no one's seen any, so for now that's just rumor. Of course, the centaurs are a mash of human, dog, and various other parts... but hey, who knows how that mutation came about. Grey was probably messing around in one of his labs.
 * The radscorpions are a result of a combination of radiation and the FEV virus, and Razlo in Shady Sands is correct - they were originally Emperor Scorpions that have grown... big.
 * FEV-Infected Critters in the wasteland include almost all the ones you've seen in F1 and F2:
 * Creatures not mutated by FEV probably did not survive the aftermath of the Great War, with the possible exception of cockroaches... and perhaps normal ants, though there are FEV-infected versions of these species.
 * No one knows where those bird noises in Vault City came from.
 * I'll try to include a chart of FEV-infected creatures in future additions as well as other critters that you may not have seen in F1 and F2. Most likely a great majority of insects were affected (they tend to breed much faster, and their mutations tend to become evident pretty quickly as the generations advance), possibly beetles, some spiders, cockroaches, and other creatures." Their increased mass and strength makes them highly dangerous to large prey and even humans, as their mandibles are capable of cutting through leather, plastic and even bone. Their exoskeleton can shrug off punches and most kinds of blunt trauma but remains vulnerable to firearms and sharp weapons. Great ants are also quite sensitive to antennae trauma. Damage to their primary sense organ reliably sends them into a frenzy, attacking anyone and anything in the vicinity. Like their forebears, ants have a strong swarm instinct and will attack prey in packs or double-down to protect the nest if their queen is threatened in any way. 

Ant


Large and small forager ants make up the bulk of these ants' colonies, while soldier ants guard them to apply defense. Small, flight-enabled swarms also exist and act together as if by a hive mind in the group. Ants are not a serious threat, only being dangerous when swarming the player character due to encroachment of their territories.

Giant ant


The common variant of a giant ant, without a specialized role in the swarm. What they lack in individual fortitude, they make up for with relentless attacks and swarm tactics. Their exoskeleton isn't particularly thick, but it can turn aside weak punches and dull knives. Their mandibles can cut through most leather and plastic with ease, even snapping bones on a lucky hit. Giant ants become particularly aggressive when their queen is threatened.

Giant ant queen


The heart of the swarm, a giant ant queen is significantly larger than drones and soldiers and capable of spitting acid at attackers. However, her large size renders her largely immobile, while the wings are little more than a vestigial limb, capable of threat displays, but little beyond that. The queen is roughly four to five times larger than the average giant ant. When threatened, she buzzes her wings and will hiss at the enemy. She will then proceed to spit an acidic saliva at the enemy in an attempt to ward them off. She cannot move much, so avoidance is easy, especially in smaller spaces.

Giant soldier ant


These are the colony's main defense against intruders. They are plentiful and can often overwhelm an enemy by either running it off or killing it on the spot; usually the latter. This ant can often be found accompanying smaller ants as they forage.

Giant worker ant


As their name suggests, these ants do most of the work around the colony.

Invader ant


Two of them may be found attacking the mutated forager ants in Shalebridge tunnels.

Mutated forager ant


They are friendly and won't attack, even if they are attacked.

Giant albino ant


A rare variation, these are found in the Hoover Dam Scum Pits. Their exoskeleton is a very pale yellow that almost looks white. Their eyes glow red like the giant albino rat, and their mandibles glow green and drip an acidic green fluid. Small numbers of these ants live in a nest back in the office area. They are ravenous and will come out fairly often to catch and drag a rat or leech back into their dark lair.

Giant albino ant queen


The giant albino ant queen is found in the ant hive located in the Scum Pits of Hoover Dam. Unlike the giant albino ant, the queen's exoskeleton is only very pale on her abdomen.

Appearances
 Giant ants appear in Fallout 2, Fallout 3, Fallout: New Vegas, the Nuka-World add-on for Fallout 4, Fallout 76, Fallout Shelter, J.E. Sawyer's Fallout Role-Playing Game and were due to appear in Van Buren, the canceled Fallout 3 by Black Isle Studios. A friendly giant ant called Mr. Pinch is used as a mount by the Puppet Man in the official One Man, and a Crate of Puppets comic by Penny Arcade.

Behind the scenes
Like many other creatures in the Fallout series, the giant ant draws from old black and white cinema, particularly the movie "Them!".