Why Is My Prayer Plant Opening At Night?

Question

It opens at night and folds up during the days.

Answer 1

It may be experiencing stress such as low humidity or too much direct sunlight. These plants need high humidity, indirect light, moist soil (except in winter), and filtered or distilled water. Is the plant in a darkened room at night? Is it light during the day? Prayer plant moves its leaves in response to darkness.

These care tips should help:

https://plants.ces.ncsu.edu/plants/maranta-leuconeura/