Can dogs be afraid of the nightime?

My dog is usually pretty chill and if I go to sleep during the day afternoon, he usually stays in his bed when I go to mine but, every night when I go sleep, he ends up scratching at my door excessively and whining loudly. It's so incredibly annoying and the reason why don't just let him in is because he'll just end up scratching on the door again to be let back out forcing to get up constantly to let him and out all night. It seems to me that he's afraid of the nighttime since it's the only way he acts like that. Does anyone else here have the same problems with their dogs?