These small red ants regularly do this swarming behavior on our sidewalk and on the lawn grass.
These several images show the ant crossing a field of bird's nest fungi, removing one "egg" from a nest, and moving it away. The fungi were on the underside of a cow dung. The ant moved the "egg" over 10 cm during the time I was photographing and observing it. The fungi can be found at observation https://www.inaturalist.org/observations/216246811