1、 How do I turn back at night

When the sun set, there was no sunshine. It will swing back slowly, rather than "turning back" as rumored. When there is no light, the auxin in its body will be rearranged and distributed relatively evenly, so that it can slowly return to its starting position. At about 3 a.m., it has turned back to its original position and will face to the East, waiting for the sun to rise and rotate with the sun for a new day

2、 Why is it always facing the sun

From its bud just grows to its flower plate in full bloom, it will face the sun in order to absorb sunlight and obtain nutrients. The auxin on its back will rise, stimulating the cells on the side with light on their back to slowly elongate and rotate with the sunlight. But when the flower plate is in full bloom, it will no longer rotate with the sun, but will be fixed towards the east to obtain nutrients