Tiny pods scurring about our tank are sometimes problematic, but not these guys. These are Mysid shrimp, which are very small and rather translucent. For a comparison, please note the size of the grains of sand in this image. Wrasses, mandarins and more would be happy to snack upon these little morsels of food. These appeared recently in my tank and may exist in my refugium, and this is the best picture I can get. Reef-safe.
The first picture is a feeding dish filled with pods to feed to some tiny cuttlefish. You may notice some amphipods in the same picture as well, but mostly it's mysids. Mysids are saltwater; mysis are freshwater.