HI

I have started to notice this "trail", not sure what else to describe it as around the top of a few of the doors around the house. The door frames are wood and i have seen it on no other type of surface. I was thinking maybe termites, but im not sure as the "trail" does not seem to have any movement or obvious insects coming from it.

Any ideas on what it is or/and treatment?

We get them, I assumed termites and got rid of them with the Chaindrite crack and crevice spray. I could actually see little insects if I looked really closely.

Termites. If they are in the door frames, the whole are will be infested.

Yep, termite trail. Clean off the trail and spray with something like Chaindrite or similar crack and crevice spray. Repeat every few days until no sign of the little buggers. Beware these sprays are quite toxic so spray and leave room quickly.

Or get a professional company like Chiang Mai pest control to come in and spray plus they drill small holes in the wood and inject chemicals.

Thanks for all your help everyone.