From Brian Williamson:
Having followed the activity of several Lasius brunneus nests in various locations in Epping Forest during the Spring and Summer I have been surprised by observing workers still active, albeit sluggishly, whose nest is located in a large, sawn section of tree trunk. Although in this part of the country weather conditions have been fairly mild the last two nights have been frosty yet on checking this nest today(11th December, 2013) I observed two workers moving between nest entrance holes and on checking some twenty minutes later saw one more. This is the latest date recorded for any ant nest activity so far, in previous years I have seen nothing after early November.
From Brian Williamson:
Today (Saturday 17th May, 2014) I collected a dealate Lasius brunneus queen on the bark of a mature oak in an area of Epping Forest known as Bury Wood. The weather conditions were more akin to a day in July with the temperature around 23 degrees C.and very light winds. The earliest date for finding queens before today goes back to the 26th May 2007, the weather conditions on that day were temperatures of 24-25 degrees C and very bright sunshine and no wind. I continued my search for approximately forty five minutes after the capture but did not find any further specimens. It may well be that there will be more alates at large if the current warm and still conditions persist. Lasius brunneus is abundant in all areas so far searched in the forest.