Fire ants
Any of a number of species of red ants which, unlike normal ants which bite and spray an acid on the bite, fire ants bite and then sting from the abdomen, which results in a painful sting.
For people who are allergic to this sting, the reaction can be serious and even potentially fatal. Anyone exhibiting signs of an allergic reaction should receive medical attention immediately.
In Amtgard terms fire ants are unfortunately often found in the same parks used by Amtgarders.
This is particularly true throughout the american south, where the Red Imported Fire Ant (Solenopsis invicta),is the most common species. After being introduced accidentally in Mobile, Alabama, they are now found throughout the south, including Texas.
A rumored illegal and extremely discouraged amtgard "dirty trick" involved finding a nest of fire ants and placing an amtgard projectile such as an arrow on the nest so it would be covered by the ants, then firing it at an opponent, which would cause many of them to shake loose and cling onto the target's garb. Some variations involved doing it with a sword, though this of course risked them ending up on the wielder. Supposedly this tactic was to be used only on people believed to be Sluffing.
While some found it funny, it was also a potential nightmare situation should said target have been allergic to fire ants.
Some years ago there was a controversy on Amtgard-L after Sir Father Thomas bragged about using this tactic on Aramithris.
In some places, the term "fire ants" is a slang reference to a group of Saracens.