Keep observation gentle
A room light or a brief low-intensity look can show shrimp moving across plants and hardscape after the main aquarium light is off. Avoid repeatedly startling the colony.
Do not assume red light is invisible to shrimp or use a bright beam close to them. The safest observation is one that does not trigger a sudden retreat.
Record what you actually see
Note the time, tank lighting, and where shrimp are active. A small number visible in a night check does not tell you how many are hidden elsewhere.
Compare observations across several evenings instead of drawing conclusions from a single look. Plants, shadows, and hardscape create many places that cannot be seen from the front.
Use nighttime activity as context
After-dark grazing is one part of a daily pattern, not a guarantee of a particular feeding need. Keep the regular diet and maintenance routine consistent.
If the colony changes activity at all hours, check water readings, temperature, and recent disturbances. A time-of-day observation becomes useful when paired with other evidence.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.