Oh, and for some reason, there were also huge numbers of woodlice out and about on the tree trunks.
When would you expect to see the woodlice out and about normally???
Usually they don't make their presence felt where I live, at least not in conspicuous numbers, until late March at the earliest. Usually, I only see the odd one or two hardy ones active outdoors during December and January, not the small armies of them that were occupying the Horse Chestnut trees!
Later in the year they appear in abundance when warm enough rain descends in the right quantity. Not too little, not too much.
In the past, January temperatures would have been too low for them to emerge from hibernation, but this year we're starting with the sort of temperatures that usually don't arrive until April!