I have this old 2x4 that we removed from somewhere in the house and which has been sitting outside in a pile with other lumber for a while. I wanted to cut a small piece from it and noticed that one end has these tubular marks filled with powdery particles resembling saw dust. The wood is relatively dry and when I removed some of that substance I didn't see any insects or anything with my naked eye.
Should I be concerned that this was sitting next to the house? Is this evidence of previous termite infestation or something else? And is it okay to use a piece from the other end of this piece that doesn't have any such marks?