Are these termite droppings. If so, can I do some sort of localized treatment?
This house was tented in the past 4 years. This is the only place I’ve seen any kind of pest.
Updating this question with some new images, since there was some confusion about the context. Here is an establishing shot:
Here is a close up of the suspected frass:
Here is a close up of the top of the window, where I speculate the frass is being pushed out of the wood and falling onto the sill below: