PEX Protection Ideas - Rodents in crawlspace with galvanized pipe

[Pierre E.]

Hey BP Fam!  I need to replace galvanized pipe (within house, in crawlspace, and to the street).   Single story 2 bath house with crawlspace kitchen and laundry room all on one side of the house

1) - Need to decide between what material is best Copper, CPVC, PEX. (Prefer copper, concerned about evidence of rodents in crawlspace and potential for chewing hole causing leak for PEX, but PEX might even be main/only option based on what available plumbers will do, copper might be too difficult/dangerous under crawlspace? and cost? and CPVC might not be allowed in some places I heard?)  Thoughts on type for repiping?

2) If PEX, thoughts on protecting it from rodent damage?  Is it possible/allowable/cost effective to maybe have a "crawlspace bulkhead" to run them through or any other ideas or option some sort of tubing or conduit? Maybe the metal ducts stuff (the solid straight kind used for dryers with some flexible stuff for bends)? (totally unsure of cost)

3) Also if PEX, would that be appropriate to tie to street? Would that need to be copper to the main, or to the PEX Manifold and then start the runs of pex in the house?

[Lisa Wright]

I didn't even consider that rodents might chew it.    A quick google says that it can get chewed through.  I wonder about doing copper under the home and pex inside the walls.  Or doing regular treatments down there with ammonia or moth balls so no one sets up house if there is an issue in the area.  
If there is no issue I'd make sure it's secure and watch for activity.  

hmmm.  I can't wait to see what the pros say.