I have noticed that one of the joists in our crawl space has a small crack in it, and near to it are some small (1-2 inch long) fissures. I didn't notice it at the time, but in the photos (see below) the small fissures appear to have some yellowish liquid inside.
I would like to know if this is a natural feature, or a sign of insect damage. I couldn't see any other signs of termite damage (e.g. mud tubes) and the rest of the joist looks fine. I tried to stick a screwdriver into the joist but it seems to be solid on both sides, and the bottom, near to these features.
I would be grateful for any suggestions on what this might be.