ants travel HOW far?

[t-keela]

In this report
Doug seems to forget what I thought was the point of the question, "How far will ants wander in search of food? or just how far away can an ant nest be located from a food source?"
I appreciate the response given regarding chemical trails and self-sacrificing for the good of the community and all. But, how FAR will ants wander...
Surely there is some data documenting the number of feet, yards, or miles even that different species of ants have been observed from their point of origin.
Having planted several gardens before I know that some ants will travel great lengths in order to find the goodies they haul back home. I've seen thousands in long columns scaling very tall trees to reach their buffets in the tops. Once on the ground they may still have a long trek across rough terrain.
So, how about it Doug? What's the record on long distance ant foragers? I hear they've got some serious roaming ants down under.