They're certainly less defensive in the daytime. Come near a hive at night though, and ho ho ho is it bad news.
Fire ants suck. I'm sure Quickman knows, but they're an invasive Columbian species with no natural predators on this continent. I was reading about a parasitic fly that lays its eggs in other bugs. The larvae eat the brain and nervous system, until one day the head just falls off. 3 or so days later, out come little fly babies.
What's really interesting is the behavior exhibited by afflicted bugs. The ants will wander aimlessly, separate from the colony, and stingless bees, which have been known to be targets of the Pharadae fly sometimes, forage at night and fly towards light like a moth. That has to be cool to see.
I used to be deathly afraid of being stung, but then I realized either it doesn't really hurt that much, or I have grown a high pain tolerance.