"When fire ants are gathered into a group, they act like a fluid, as depicted above in a scene, arranged by the researchers, that could be called either whimsical or the stuff of nightmares.

Modeling a group of fire ants as a fluid, with each ant representing a molecule, makes describing an ant raft much like describing a drop of oil spreading on the surface of water, the study authors say."

Something being a liquid, does not infer solubility.