Spiral Mound of Earth Excreted by Soil Dwellers
Puzzle 11 of The Moon Hard Pack
Question is: Spiral Mound of Earth Excreted by Soil Dwellers
and the answer is: WORMCAST
Word Meaning:
WORMCAST — A small pile of sand or soil, the end product of the breakdown of organic matter by an earthworm.
Definitions from Wiktionary.