What is the primary purpose of carpenter bees boring into wood?

Carpenter bees bore into wood primarily to create nesting sites for their young. The female carpenter bee drills tunnels into soft, untreated wood where she can lay her eggs. These tunnels serve as a safe environment for the larvae to develop after hatching. While they may be seen feeding on nectar from flowers, the act of boring into wood is specifically for nesting purposes, making this the correct choice in understanding their behavioral patterns.

Other provided options do not accurately reflect the carpenter bees' nesting behavior; they do not typically seek food by boring into wood, lay eggs in soil as some species might, or create nesting sites for other insects. Instead, the primary function of their boring activity is singularly focused on reproduction and ensuring the safety of their offspring.