Crustaceans are a sub-phylum of arthropods that have all the eye “designs’ found in animals. Dorsal light reflexes are widespread in many aquatic animals, including crustaceans, and are behavioral responses to light in which the animal presents its dorsal surface towards a light source. Branchiopods are a group of crustaceans that are often found in temporary pond habitats, and are thought to predominantly use light cues for orientation. Fairy shrimp (Branchiopoda: Anostraca) are unusual because they generally swim with their ventral side upward, which correlates with the direction of light that is typical for temporary pond environments. Fairy shrimp could use a ventral light reflex for orientation purposes. In other arthropods, such as flying insects, simple eyes called ocelli are used for stabilization and orientation during flight. It remains to be seen whether anostracans generally use their simple eyes, or compound eyes, for light orientation in their habitats. Here, we summarize findings of the dorsal light reflex of a subset of crustaceans. We also ask: how widespread are ventral light reflexes? Could excitatory/inhibitory pathways for reflexive behavior be reversed in fairy shrimp?