I think you are talking about Teredo spp, a mollusc that attacks wood in marine environments - 'shipworm'. One of the reaons they copper-bottomed old wooden ships.
I think your question has been adequately answered. I think the main points to remember from this thread are:
1. Don't panic, unless you see fresh frass, have a damp problem in a cold damp house the majority of flight holes that you may find are usually ancient.
(always be more suspicious of introduced wood into the home though)
2. If you get given some wood from a nice farmer/wood working friend which has been felled recently and spent some while in a damp outdoor environment AND you see holes in it, it may be wise not to use that section of timber as the creatures that made them are probably still alive.
3. If you have a non centrally heated old cottage and you find frass and fresh (large) flight holes in your oak/elm beams then disregard point 1, allow yourself a brief panic, then call a professional.
Thank God I'm not a ship, ship worm sounds painfull.
I am a wood finishing expert, not a botanist! I think others may have answered better than I.
Using common sense I would presume it is because forests are not normally centrally heated, infact I believe dampness is quite a common feature, by the process of natural selection only those larvae that thrive in damp conditions would have survived... hence modern central heating systems are very un-forest like in their ambience!!!
I am not sure what physiological effects this has on them. I usually find woodworm damage at the corners of floors where they abutt a damp wall for example and the wood is damp. If you are just trying to wind me up then I am obviously too tired too see. I am sure if you sent an email to David Bellamy he could elaborate.