Termites in your trees can be a major problem. Termites rarely feed on live trees, so if your tree is infested then it probably has a significant amount of dead wood. If your tree is not sick, then the culprits are likely Formosan termites which feed on certain species of live tree. These "super" termites have colonies with millions of members and they are all voracious feeders. If you don't rid your tree of termites, whatever the type, it won't be long before they realize that there is much softer and tastier wood to be had in your house.
Treat the infested tree. Use a commercial pesticide approved for yard and garden use like Demon TC or any other similar product. Only treat your tree in the late afternoon on a day when there is little wind and no rain forecast for the next few days.
To treat the exterior of the tree and nest, fill a spray bottle with pesticide that has been diluted according to the manufacturer's instructions. Then spray the exterior of the tree where you have observed damage or activity. Next, carefully inspect the tree for termite damage. Gently pull on the bark to see if it can be easily removed to reveal damage underneath and then spray the area. Inaccessible internal damage to the tree and the interior of the nest will need to be injected with pesticide through a drilled hole.
Apply termite bait stations around the perimeter of your home. If there are any termites feeding close to it, pop-up indicators will alert you that its time to call the exterminator.
Call a tree doctor. If your tree was infested by common termites then they were likely feeding on dead cellulose in the pith or cambium layer and the source of the problem needs to be diagnosed. If the tree in question is an Oak, Ash or water-bound Cypress, then the culprits were likely Formosan termites and the damage may be extensive.
Call an exterminator to inspect your property and home. Termites may already be feeding on your home or other trees sight unseen.