Ant nectar addiction
Only ant nectar causes this addiction, as fire ant nectar is not addictive. Also note that this is the one addiction that cannot be cured by employing the My First Laboratory. One must employ a doctor to cure this addiction, or else its effects must wane away with time.
Fallout: New Vegas
It is only possible to become addicted to ant nectar, although the 5% chance is one of the lowest addiction rates of any other addictive consumable in the game. It is further reduced by Chem Resistant, Old World Gourmet ( ), and Big Brained ( ) perks, producing a very small 0.75% chance of addiction. One will still become addicted with a 100% chance after frequent use, which is due to the UMON effect. This effect can be avoided through the use of the Logan's Loophole trait, however.
Ant nectar addiction used to be incurable due to a bug, but this was fixed in Fallout: New Vegas patch 220.127.116.11x. The console command Player.RemoveSpell 0006DC6E will immediately remove the addiction on the PC version.