这些飞行动物不是在日间活动就是昼伏夜出。

These winged creatures are either active during the day, or nocturnal.

吸血鬼冷酷、孤傲、俊美、昼伏夜出，正如喜怒无常的十几岁男孩。

Vampires are cool, aloof, beautiful, brooding creatures of the night. Typical moody teenage boys, basically.

与其他非洲野生动物相比，豹子极少抛头露面，想要一睹其真容实属难事，这部分缘于它们昼伏夜出的捕食习性。

Compared with other African game, leopards are famously shy and rarely seen, partially because of their largely nocturnal hunting habits.

水泥池养殖的杂交鲟具有昼伏夜出习性，深水网箱养殖的杂交鲟流急时在网箱底部活动、流缓时到水层中游动；

The hybrid sturgeon in cement pool had the habit of hiding during the day and coming out at night, while that in deep water cage stayed at the base in riptide and swam in slack tide.