Fallout 3/Those!

Fire ants are attacking Greyditch, just in the outskirts of the DC ruins. While you may have a random encounter about Greyditch being burned to the ground, the quest is only introduced if you find Bryan Wilks or Doctor Lesko. Bryan Wilks will usually approach you at the Super-Duper Mart, but may be found in other places.

Bryan Wilks will run up to you in a panic, saying the ants took his father. You can talk to him to get some more information, and with the appropriate perks or abilities, you can get information about the location of useful items (such as a dumpster behind the diner).

Wilks residence
Bryan Wilks' father was already dead, with two dead fire ants in the house. However, you can get a shack key from the body, and collect information on Dr. Lesko.

Of the other residences: The other residences don't contain too many items of interest, but Brandice's House has a timeline of what happened.
 * Brandice's House has a timeline of the ant attacks. There is also mention of weapon behind the refrigerator, a .32 handgun.
 * The abandoned house next to Brandice's House contains one of the Guns and Bullets ../Skill Books/.

Marigold Station
As you can determine from the nearby shack, Marigold station seems to be the location of importance. It is located at the southern part of Greyditch.

Dr. Lesko
Dr. Lesko was intended to reduce the size and threat of the ants by injecting FEV mutagens into the eggs, but made a mistake in doing so. Instead, he caused the ants to breathe fire rather than become smaller.

He wants to keep the Queen alive, and asks you to kill the nest guardians to give him access to the terminal. To get the best reward, you should ask him for an incentive.

Dr. Lesko is a good character. If you complete what he asks to do, he will hive you either the Ant Might or Ant Sight perk, which boosts Strength or Perception by 1 point, and gives you a 25% resistance to fire. The lab coat provides radiation resistance, and +10 science.

Grady's Last Recording
In the metro station, you can find a recording about the naughty nightwear. The key for the safe is in the firehose in a closet, and the safe is in a room with three spinning lights (north of the Dr. Lesko's lab.)

When you get the Naughty Nightwear, Lug-Nut will come and demand you give it to him. A speech check can be used to get rid of him, but you can use other means of dealing with him.

Bring this to Ronald Lauren in Girdershade.

Bryan Wilks
When you return to Bryan Wilks, he will mention that the ants all killed each other. However, there is a concern about him needing a new home. If pressed in conversation, he suggests contacting Vera in Rivet City, she is the owner of the Hotel within the city.

The main options is to contact Vera about Bryan, who will happily adopt him. You may also leave him at Greyditch, or at Little Lamplight. Choosing either of these options provides an experience reward. If you are short on caps, you may also head to Paradise falls and sell Bryan for 100 caps (300 via speech check.)