White oak, cherry tree problems

The white oak has dark spots low on the trunk where I’m seeing insects. The spots look almost like oozing sap but aren’t sticky or wet. Red ants at base, and something smaller, black body with wings, buzzing around the spots a bit higher up. Also, the crown seems sparse compared to other nearby white oaks.

Winged insects visible in last few seconds.

These are photos of what I believe are cherry trees (they didn’t fruit last season but there is green fruit on it now). During the heavy rains, both trees split and I’m trying to decide if I should just remove them completely or try to cut the splintered limbs away to see how they fare.