It is a good idea to cover your budgie’s cage every night. First of all, it will help him to stay quiet if you want to sleep past sunrise. It is also important for your budgie to get enough sleep, so if your budgie goes to bed after sunset, his cage should be covered after sunrise long enough for him to get plenty of sleep. Also, covering the cage can help prevent night fright. Night fright occurs when a budgie is startled out of its sleep and thrashes wildly about the cage, possibly injuring himself. A covered cage will provide some security, as well as provide a buffer to prevent sounds and movement from startling him. In case your budgie does get night fright, make sure to either use a light sheet or leave a corner uncovered and have a night light in the room. The little bit of light will allow him to calm down faster and find his way back to his perch in case you are not there to turn the lights on during a fright.