>> and they were in various parts of the turf mound, not necessarily in the bottom half inch
>> where they'd need to be to validate any speculation about the founding date.

This little factoid is very interesting and in a desperate attempt to stop the rot I'm gonna pick up on it.

I know nothing of the turf mound. Was it created by cutting turf and piling it up? If so then if you cut all your turf in August and stecked it up the ants would be at many levels.

If it was not done in this way then it could be that the mound was added to yearly and left to grass over every year - a new layer of soil added each year. If the new layer was added every August then, again, you would get the insects to be trapped in every layer.

The fact that the flying ants appear throughout the original turf mound actually tie it in stronger to August than if they were just in one layer, because that would just indicate that the building period spanned August.

As a side note: Within the mound at Newgrange they found several stages of building, and the insects and snail shells found at the boundaries, along with the heavy grass growth at each one, indicated that there was at least a full year between leaving a stage and starting the next one.