Winged ants were found at the base of Silbury Hill during the BBC dig in the '60's.
You can see some of them in the Keiller Museum.
The date that I've seen is c.2750bc.
I believe Dames and the BBC dig are one and the same.
I won't dispute the date. Both are Neolithic in any case.
If winged ants were found at the base of Silbury doesn't that mean that it was started in August and not finished then? Or did they build from the top down? Or have I missed the point?