Those!

Those! is a side quest $$

A small boy named Bryan Wilks will approach the Lone Wanderer as they come into the vicinity of Grayditch; this includes Super-Duper Mart or Sewer Waystation, but can be as far as Wilhelm's Wharf.

He will then ask the player character to help him find his father, Fred Wilks, who seems to be trapped in the town infested with Fire Ants.

Detailed walkthrough
During the first two stages of the mission, Bryan will be hiding in the Pulowski Preservation shelter near the diner.

Find Bryan Wilks's father
Bryan Wilks will approach the Lone Wanderer in the area outside Grayditch, where he tells them that he, his father, and the other dwellers were attacked by fire ants. He then asks the player character to look for his father in the town. The father's body can be later found in his house by the shack, killed by the fire ants. The player character can loot a Chinese Assault Rifle and some ammunition off the shelf in the house and the shack's key from the body of Bryan's father. In the shack, the player can find Doctor Lesko's equipment and terminal. Read the notes on the terminal to receive the Marigold Station location and the option to proceed there to locate the source of the fire ants. Also, with a mildly challenging Speech check or the Child at Heart perk, the Lone Wanderer can convince Bryan to give them the key to a dumpster behind the diner with some random loot.

Find the source of the fire ants
While searching the Marigold metro station for the cause of the fire ant infestation, the player character instead finds Doctor Lesko working in a makeshift laboratory. He explains the origin of the fire ants, particularly their ability to spit fire. The Lone Wanderer can choose to help him reverse the effect or deal with the giant ant queen themself.

When speaking with Doctor Lesko, if the player character asks for a "serious incentive," he will offer his old lab coat along with bonus perks. Lesko's Lab Coat provides +20 Radiation Resistance and +10 Science.

The player character will find the fire ant queen in the Queen Ant's Hatchery, beyond Dr. Lesko's lab. It is guarded by numerous fire ant nest guardians.
 * Path 1: Kill only the fire ant nest guardians guarding the fire ant queen and return to Dr. Lesko for a choice of either the Ant Might or the Ant Sight perk.
 * Path 2: With a Speech check or a high enough Science skill, the player character can kill the fire ant queen and convince Lesko that it's the best for humanity and get one of the perks. The player character is awarded positive Karma if they take this path.

(Optional)
 * Hack the terminal in the hatchery (requires 50 Science) to send an inhibitor pulse which will kill all fire ants found in the Grayditch area (excluding those in Marigold station).
 * Hack his terminal in the hatchery (requires 50 Science) to destroy the mutagen sample (which is the FEV). The Wanderer is rewarded with positive Karma. Having done this, the player character must pass a speech check or have Science 70 to convince Lesko that it was best for humanity.
 * Kill Doctor Lesko and receive negative Karma. The same happens if the player character lies about the protectors being dead: he runs into the hatchery and the Wanderer will again, receive negative Karma. The instant the player enters the hatchery, he spontaneously drops dead and the player receives the hacking objective.

Find a place for Bryan Wilks to stay
First, talk to Bryan and tell him about his father's fate and the fire ants. He is located in the Pulowski Preservation shelter to the right of the diner in Grayditch. The player character is then given the option of helping him find a place to live. Bryan will tell the Lone Wanderer that a cousin of his lives in Rivet City. He is talking about Vera Weatherly, owner of the Weatherly Hotel. The player character only needs to find her and mention that Bryan needs a place to live and she'll happily agree to take him in. One is awarded considerable positive Karma for choosing this option. With the arrangement made, simply return to Grayditch and tell Bryan that he can move in with his aunt; he will agree to move out there, and the quest will end. When the player returns to Rivet City, Bryan will be there.

It is also possible to convince the Mayor of Little Lamplight to let him stay there, either with a speech check or via the Child at Heart perk. Be forewarned that discussing this option with the Mayor will prevent the dialogue option for Bryan's relocation from appearing with Vera Weatherly, closing off that path even if Bryan has not been told of his potential new home. Since this is not as good an arrangement for Bryan, no Karma will be awarded either way.

Alternatively, the player character can go to Paradise Falls. Talk to Eulogy Jones, and tell him they have a child for sale. He will offer 100 caps initially, but one can receive 300 Caps if the player character passes a speech check. The Lone Wanderer will receive a considerable amount of negative Karma for this despicable act, and Eulogy will give them the agreed-upon number of caps and a collar to put on the hapless youngster. The player character will then trick Bryan into putting on the collar, and can explain that it will guide him home. Again, the quest will be completed and experience points will be given. Bryan will not be seen again, even though Three Dog will mention that he is at Paradise Falls.

The player character can also tell Bryan that they are unwilling to find him a place to live (or never offer to in the first place), which will end the quest immediately. Bryan will move back into his old house and live in Grayditch by himself. No Karma will be gained or lost. However, this option is irreversible, even if the player has a change of heart later. For example, even if the player character encounters Vera Weatherly later in the game, the dialogue option for getting her to take Bryan in will not even appear.

As long as the player character does not sell him to the slavers, they will get the 300+ experience points (XP is still rewardable for doing this on the 360 and the PS3).

Finding Bryan
Bryan usually finds the player character, most often on their first trip to Super-Duper Mart. If he does not, or if he approaches the player while they are in combat and gets scared off, here are the other places they may find him:
 * Standing on a sidewalk in Grayditch: to the west of the diner, up a hill, and across the bridge in front of the Talon Company Camp.
 * The southern entrance to the scrapyard.
 * Granny's Shack at Wilhelm's Wharf near the river near Grayditch.
 * Talking to Doctor Lesko will also give the player character Bryan's location on their Pip-Boy.
 * The player character may encounter a Wastelander telling them to "run for your life!" and that "they burned Grayditch to the ground," and a map marker for Grayditch will be added. The encounter does not give the quest, even upon entering Grayditch and the player must find Bryan Wilks or Doctor Lesko on their own to obtain the quest.
 * The player character can also acquire the quest by looking in the recently built shack (lock varies depending on the player's stats) in Grayditch, then hacking into Lesko's computer. (Xbox 360 version and PC version.)

Reward

 * Lesko's Lab Coat
 * Ant Might OR Ant Sight perk
 * 300 XP
 * Good Karma if Bryan is sent to Rivet City
 * Neutral Karma if Bryan is sent to Little Lamplight or left alone in Grayditch
 * Evil Karma if Bryan is sent to Paradise Falls

Behind the scenes

 * This quest was inspired by the 1954 Sci-Fi horror film Them!, a story about early New Mexico atomic tests that cause common ants to mutate into giant, man-killing ones.
 * Bryan will occasionally make comments from inside the fallout shelter. One of these comments, "Now I know what a TV dinner feels like," is a reference to Die Hard, in which Bruce Willis says the same line while crawling through a ventilation shaft.

Bugs

 * After completing the quest by sending Bryan to Vera, the screen text may say completed quest "Thos!" instead of 'Those!'.
 * Sometimes, Bryan will not be in Grayditch and will be standing underwater near Wilhelm's Wharf. It will not be possible to interact with him, rendering the quest impossible to complete. To fix this, he can be pushed out of the river to the nearby shore.
 * Companions will automatically start attacking the ant queen, which will not result in failing the optional requirement of not harming her, but Doctor Lesko will still know that the ant queen was harmed.
 * Sometimes Vera will be missing, causing the quest to be impossible to complete and get good karma.
 * Occasionally while attempting to leave the ant queen's hatchery, the ant queen will appear directly on top of the player character while in the cave tunnel. From that point on she is usually stuck but can still turn and attack the player character. This can result in the tunnel being blocked so the player character is unable to return to Dr. Lesko without killing the queen or with neither Lesko or the player being able to return to the hatchery without killing the queen.
 * It is possible to trigger the initial conversation with Doctor Lesko without opening the door to his lab if one gets close enough.
 * Sometimes, after completing the quest, GNR will not make an update regarding the quest.