A close-up grooming movement
Shrimp use their small appendages to clean body parts and sensory structures. A brief brushing motion can look unusual if you have not watched the animal closely before.
Observe whether the shrimp returns to grazing and moves normally. A single grooming event does not establish a health problem.
Look at the whole aquarium
Check whether multiple animals behave differently, whether the filter is working, and whether anything was recently added to the water.
A repeated pattern paired with lethargy, loss of balance, or deaths deserves further investigation. Use water tests and the product history rather than diagnosing from a video clip alone.
Avoid treating ordinary behavior
Do not medicate the aquarium because one shrimp cleaned itself. Treatments can affect invertebrates, and a product label may not cover shrimp safety.
If a concern continues, document the behavior and consult a qualified aquatic professional. Normal grooming is easier to recognize when you have a baseline for your own colony.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.