Who knows the allusion "ants become graves"

According to legend, Wu Sangui fired a cannon in Daying Village when he was fighting water in the Western Expedition. As soon as the guns rang, Gunai died outside the village. This "Gunai" was childless and lived alone in the village. After the incident, the old man in the village organized the villagers to bury her the next day. Who knows, it rained that night, and someone came the next day. The new soil has become a grave, and countless ants continue to move the soil into the new grave. The owner of this land is Ou, and the villagers all say that the "Ancient Nai Tomb" is a treasure trove of geomantic omen, suggesting that he regard it as his ancestral grave. Later, the family named Ou rebuilt the tomb, and the population has flourished since then. At present, with the expansion of the city, when the land here was expropriated by the government, Ou Jia moved her to another place with the specifications of the ancestral grave.