It certainly looks and sounds to me like termites. And it looks like they have a good hold on your house.
Take a butter knife and break open the "tubing" they have made. If you find maggot looking things inside the tubing, that would be the "workers", the ones that causes the damage.
You may think you can't afford an estimate, but in actuality, you can't afford "not" to. The termites will literally eat your home out from under you. And they do it in pretty short order.
I hope by now you have had the exterminators rid you house of the termites.

__________________
Barb


My GOD Bless our Country and our Troops, and rid the World of terroists.