Do betta fish need light at night?

No, bettas, like all living animals, need the regular cycle of night and day. Bettas also usually relax/sleep during the night because they feel like they're in a cave and more secure. Constant light can be stressful for the fish. Even in the day, do NOT keep them in direct sunlight as this will cause the temperature to flunctuate (very stressful) or overheat, as well as promote algae growth.

No, they do not need light at night, they enjoy light but, do not keep them too close to the sun as, this may cause discomfort. They are quite easy to care for, as long as they are provided a clean environment and are fed once a day. They can live for years and years! It is usually 3-4 in a bowl and in a tank 7-8. Have fun with your betta!