forgot the pic

Cud be carpenter ants, or termites, but, my bet is on the boring bees. They leave piles of sawdust everywhere. They make a round hole the size maybe of a pencil. Thats a lot of sawdust, dont let that go in that vent I see there.

"Boring Bees?" Carpenter Bees leave very obvious large holes in surfaces and are readily identifiable. Also, sawdust will accumulate directly underneath the holes.

Looks like evidence of carpenter ants, which I had to deal with twice in my previous house. You won't see a lot of apparent activity or holes...just the sawdust. They excavate the inside of wood framing and timbers and can cause significant damage. The question is whether this is from old activity or if this is current. Might be best to consult a reliable pesticide inspector.

Some places, call them carpenter bees, but, here they are called boring bees. Yep, that is a picture of their holes. At my last house, they would attack my eves. I would spray inside the hole, and take a piece of dowel, and put glue on it, and pound it in, sand it level, put a bit of wood filler, and sand again, and prime it and paint it.

And just to be clear to the OP:

Carpenter bee

Carpenter ant

Entirely different critters with different characteristics in terms of how big and how many the holes are.