Why do corals only come out in the night

Question: Why do corals only come out in the night
- Keywords:
  animal,
  coral,
  marine,
  night,
  sea
Asked by anon-207647 to Lowri on 15 Mar 2019.
- Lowri Evans answered on 15 Mar 2019:
  
  Corals have a night and day cycle, so they do different things during the day and night. At night they tend to spawn (so this forms part of their reproduction process). In the daytime, the algae that live in the coral uses the sun’s energy to make food for themselves and the coral.

Question: Why do corals only come out in the night