Nectar Collecting for Fun and Profit

 is an unmarked and repeatable Fallout 3 quest.

After completing Those!, Doctor Lesko in Grayditch (initially located in his underground lab in Marigold Metro Station, he will eventually move back to his shack after the quest) will ask you to gather fire ant nectar. He won't take ant nectar though.

Fire Ant Locations
Prior to the quest, fire ants can be found in Grayditch and the Marigold Metro tunnels; after the quest, they can only be found in the metro tunnels (if you have not killed them all, as they do not respawn even if the queen is left alive). The base percentage chance of the nectar being dropped by workers is 40%; for soldiers and warriors, 70%. These percentages are changed by the player's luck.

Rewards
Lesko pays 40 caps per sample.

Bugs

 * The French, German and Spanish translations of the dialogue only show a reward of 10 caps, which is wrong.
 * Lesko will remain in the Metro Station caves with the ant queen. Because the queen attacks you on sight Lesko will begin "fleeing", unless you kill the ant queen, but the speaking options will be limited and an option about fire ant nectar will never appear.
 * If you decide to wait and get the perk later and then complete 'Those', the speech option to choose a perk may disappear.

Коллекционирование нектара для забавы и выгоды