nocturnal

Bats are nocturnal creatures that use echolocation to hunt for insects in the dark.

(Chinese) 蝙蝠是夜行性生物，它们在黑暗中利用回声定位来捕食昆虫。

The flower is nocturnal, only blooming after the sun has set to attract moths.

(Chinese) 这种花是夜间开放的，只在日落后开花以吸引飞蛾。