#422 & 423 - Sapphire & Ruby Somniant

[Mysfytt]

I think of all ants use that formic acid - those that sting inject it into the bite - causing maximum damage. The sprayers would be one to watch though they can get your eyes. An uncomfortably large number of ants in Australia both bite and sting - some worse than wasps. Some may spray too, unsure off the top of my head on that one though.
also the Bullet Ant from south America comes to mind - its sting is said to feel like being shot by a bullet and can last for days before the pain goes away.