You didn't light it from a distance? ;)
:-) much to the confusion of the kids there was no lighting involved (fun but somewhat unadvised). The petrol did fume out much of the nest, but the little sods built a new nest just next to the underground one. I worked this out after rolling the log in-front of the hole (the next day) out of the way and this resulted in a cloud of several hundred of the little sods deciding I was their worst enemy. As it turns out only one of them manged to get me but my concerted chemical warfare attack using my newly acquired long range spray did indeed prove I was their worst enemy! Much carnage later they bother my little patch of bush no more.
Sounds like my first attempt with petrol as well, the kids watching from inside through the ranchslider were laughing there ar*es off with me sprinting away.
But it worked in the end with only one sting received on the ear.
Now I use a hose and funnel, no drama since the new method adopted.