A diverse range of organisms, from bacteria and social insects to bird flocks and fish schools, achieve collective tasks through implicit coordination. While numerous theoretical studies have been conducted, classical models of swarms often neglect the effect of the embedded environments. In this talk, I will discuss the perspective of fluid stigmergy, which focuses on how fluid environments affect the self-organization properties of animal groups. Experiments and models of red imported fire ants (Solenopsis invicta) and black soldier fly larvae (Hermetia illucens) in complex fluid environments will be presented. To conclude, I will apply this perspective to fish schools and share my ongoing efforts using computer vision and fish-like robots to reveal the coordination strategies of underwater collectives.