Dozens of very small black spheroids on a rotting (birch?) branch.
Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
No interactions present.
Definitely fungal but I cannot say which it might be.
Thanks flaxton, that's a start anyway!
Lat/Lng: 50.9158, -0.1503
OS grid ref: TQ301145
Mixed deciduous woodland.