I've got an unfinished basement with cinder block walls. I can see mud coming out of some cracks and there are white insects sticking their heads out of this mud. I think they're termites. How can I treat this area? Do I have to drill holes?
Termites do nothing but forage around looking for food and they typically do this under ground. Foundation walls which can run deep into the ground will many times cross paths with these foraging termites. Solid poured concrete walls won't let them enter but cinder block foundations are subject to cracks which can let them get inside. The good news is that if the wall is accessible from your unfinished basement, you can drill some holes through which you can pump some termiticide as explained in our termite control article.
Once you've got access holes, treat with Termidor and use the Foaming Tool to get the best coverage. And treat as much of the home as you can since once termites find a house, it's likely they'll enter at another location if the house isn't properly and thoroughly protected.