This sapling oak had these swellings bursting through the bark between ground level and about 2 feet above ground level. There were some ants amongst them. The freshest swellings were at ground level.
No identification made yet.
No interactions present.
Possibly just adventitious roots sprouting from the base of stem.
The ants may be interested in the insects inside them or something they give off.
Lat/Lng: 52.30736, 1.64208
OS grid ref: TM483739
Woodland adjacent to heathland approx 1/2 mile from sea.