
I wouldn't say - zero day time activity:
Opens every time after sensing food in the column (3 times daily for a fish in this tank).
Before that - in 6g, less fed - less open:
Started to eat in a separate container, with high concentration of the food, floating around:
Was shaded, because there were 200W lights above the kitchen counter

Later, was fed in the heated pico, with 100% water changes after thant, was there for a months.
Tried this too:
Mostly is feed by baster.
Sun or chili:
Have both, and the sun is tens times easier - only hassle to feed. But - very colorful.
The chili is nocturnal (as far as I know), and, depending how frequently the tank is fed, will be open from late evening and night only - to the significant part of the day (when food is given 8 times during the day, what is not good for a water quality).
This kind
was opened more readily, than these two:
Will continue (too much images for a single post)