Carpenter ants excavate wood to create galleries for nesting but do not feed on it; they discard the wood as sawdust-like frass outside their galleries. TheGeneral Pest Management: Guide for Commercial Applicators - Category 7A(Chapter 7: Ants) notes that this frass is a key sign of carpenter ant activity. Option A (feed on the wood) is incorrect, as they feed on insects and sugary substances. Option B (make transportation tubes) applies to termites, not carpenter ants.
[Reference:General Pest Management: Guide for Commercial Applicators - Category 7A(MSU Extension), Chapter 7: Ants.]