Yes my friend, those are termite tubes in the crawlspace. It is important that your inspector inspect the crawlspace as there are many things that can be found that may cost you a lot of money later. What? Pests, rodents, insulation problems, , plumbing, electrical, heating and cooling problems, excessive water and moisture, and mold.
Ask your inspector if he will inspect the crawlspace or will he not be able to access it?