Fire ant warrior

General
Fire ants are giant ants that gained their ability to breathe fire when Doctor Lesko manipulated the genetic code of giant ants in an attempt to reduce them to the size of ants from 200 years ago.

Tactics
Due to the added threat of their fire breath, it is best to handle them at mid to long range. Crippling their antennae will cause the fire ant to frenzy and attack all characters in the area. As with all organic enemies the head or the torso are also good areas to target. Avoid shooting the legs because they take only 50% damage (however crippling the legs can slow the ant down). Another tactic that is very useful with all varieties of fire ant is to run up to them quickly so they can't blast you with their fire breath and then stand over the top of them and beat them with a tire iron or similar melee weapon, thus avoiding their fire breath. Keep in mind, the aforementioned melee tactic loses its effectiveness when there are multiple fire ants within firing range of each other.

A good general approach is to snipe at the antennae and head at long range with the Hunting Rifle (don't waste precious .308 sniper rifle ammo on this minor pest, save it for muties and mercs) until the fire ant is either dead or getting close enough to use its fire attack. At this point, quickly step around a corner, equip the combat shotgun, and wait for the ant's head to appear. All varieties of ant are fairly quick when moving in a straight line, but are slow when turning. You'll have plenty of time to put a few shells into the bug before it turns far enough around the corner to attack you.