how to control pests with natural building?

I am just starting to delve into natural building and materials - currently am battling carpenter ants in my old cabin that I am living in.
This may be too big of a question,  but how do you control pests with natueral materials and prevent moisture ?? My understanding is wood can get wet which invites many critters, including carpenter ants, termites, etc. and natural insulations are great cozy places for rats, mice, etc.?
Thanks in advance for pointing me in the right direction to get some of this information.

The two materials that come to mind are hempcrete and cob. Both are typically monolithic in structure so there are no pockets to make good homes. They would have to chew every bit of it, and those materials are not typically something a rodent would chew on. I would guess it would also stop ants... but where I am at, ants are not really a problem, so I don't have any good experience keeping them out of the house.

***Edit, sorry. Some how I missed that you have a cabin that already has ants in it. I'm not sure about getting rid of them, but hempcrete is typically installed around a wooden frame. It would probably help prevent more from coming in... but I doubt you would really want to encase them inside the wall either.

We have a traditional stick framed home, but as we've replaced carpet with tile we've put diatomaceous earth under all our baseboards.   I think it helps a lot. If you can spray the dry powder into any areas that the insects can live in it might help.  Remember to wear a mask during this process.   While it's nontoxic chemically it's still not good for your lungs to inhale.  

April, you have a big questions that has many answers for the different situations you speak of.
There are a few basic steps taken to reduce insect infestation;
- design to prevent, water ingress, insects via stumps by fitting metal caps on stumps, ground clearance
- building practises to ensure the design is actually put in place, people take short cuts
- Chemicals are used sometimes, applied to the ground
- mechanical processes are applied stumps, wall joints, roof flashing, guttering if needed

I would research under;
- 'preventing pests entering buildings'
- 'preventing moisture ingress'
- basic steps for safe home building
for a start.