The Beneficial Red Wood Ant

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I've been fascinated by the behavior of this species of ant since we moved to the mountains 22 years ago.
They thatch large mounds in the forest out of pine-needles and wood debris, usually in a dead tree stump or fallen log and these mounds, which shelter the colony, are sometimes 3 feet high and 4 to 5 feet wide at the base.
I often see the ants carrying large sections of pine-needles, or even entire needles, back to the colony where they carefully place the pieces into the ongoing construction.
Three years ago I discovered one of these colonies in a vacant city lot that was about to be developed, and not wanting to see the colony lost, I dug it up and transplanted it to the native plant section of Earth Home Garden.
My son helped me dig up the rotted wood & pine-needle mound, shoveling the whole mess onto a tarp in the back of his pick-up, in hope that the queen might survive and the colony could continue on in our yard.
The transplant was successful, and after moving themselves to a different, apparently more suitable log, the colony is thriving and the mound growing larger each year.
It was suggested to me that these might be Carpenter Ants, which could eventually destroy the frame structure of our house, but after researching Carpenter Ants on the internet, I couldn't find a species of Carpenter Ant that resembled this one.
So I e-mailed photos of the ants to the legendary E. O. Wilson---Professor of Science and Curator in Entomology, Museum of Contemporary Zoology, Harvard University---probably the world's foremost ant expert, author of 'The Diversity Of Life' and, with Bert Holldobler, 'The Ants'.
Dr. Wilson generously took the time to identify the ants for me, and e-mailed a very kind reply.
It turns out that these ants are not a pest, but actually a species of Formica rufa ants (or Wood Ants), a very beneficial insect, one species of which is used for pest control in some forests of Germany, where they transplant colonies much as I did, into pest infested forest areas.
Now that I know what type of ants they are I've found more info on the internet, and some studies seem to show that native plants growing in the vicinity of Wood Ant colonies are healthier because the ants feed on insect pests, and there is also evidence that the presence of Wood Ants increases soil fertility.