Jim,
Woodworm make the holes when they exit the wood, the eggs are laid into the wood by the thingy that lays them and they then hatch and the little shits then eat their way out and wander off to infest to procreate and bury the next round of eggs in your treasured wood pile.
It used to be the practice to have a sacrificial piece of wood in your roof (to protect the beams) that was usually alder, the wood of choice of the thingy that lays them. Regardless of whether there is any evidence of woodworm activity, take it and burn it once a year whilst shouting got you you little bastards and still feeling smug, replace the piece of alder to last another year. Woodworm can exist in wood for up to five years before they emerge and announce their presence. Liquid treatments in stocks of wood such as ours are somewhat useless as they only treat the surface, which we of course recreate every time we use our bandsaws.