Growth and Die-back

Mycelium grows only through dirt-like blocks, one block at a time, towards the nearest target. If 16 steps in a row bring it no closer (a floating island, a wall), it gives the target up for 5 minutes. With nothing to reach it explores up to 8 blocks.

Busy strands thicken (4 stages) and carry items faster. Strands that serve nothing starve and turn back to dirt in about 25 seconds. Cut-off pieces die at once; a cut strand drops its cargo. Strands you led with bait or pheromone stay.