biology - Plausible reason for gold-digging ant - Worldbuilding

Medieval bestiaries describe a creature, a type of desert-dwelling ant that digs for gold. It was also said to be the size of a fox, but I'll ignore that in this question. Why would ants unearth p

Gold-Digging Ant by BangBooDoragon on DeviantArt

Midnight Devilwitch BlingBling (Ref & Lore Pt1) by InsaneSpyro

Planet of Hats - TV Tropes

AUU Races, SpongeBob & Friends Adventures Wiki

Gold' Digging Ants to Purple-Coloured Beards: 5 Ways Ancient India

Ants and termites help in the discovery of gold

Gold-digging ant - Wikipedia

Worldbuilding - Atomic Rockets

AUU Races, SpongeBob & Friends Adventures Wiki

Herodotus's Legendary Fox Sized Gold Digging Ants