Some people cover their bird's cage at night.
Some people never cover their bird's cage at night.
Some people sometimes cover and sometimes don't cover their bird's cage at night.
The yes answers and the no answers are equally good answers to the question. The sometimes answer is not as good.
If you cover your bird's cage most of the time, he/she becomes used to this and may not sleep as well without the cover on the nights that you do not put it on. If you do not cover your bird's cage most of the time, he/she may be frightened when you decide to put it on one night.
If you keep your bird in the livingroom and are often up past his bedtime, it is a good idea to get him used to the cover and cover him every night so he gets a good night's sleep.
Another option if your bird stays in the livingroom is to have a night cage in a quiet room where you can put him at bedtime. There would be no need to cover this cage unless your bird is used to being covered.
If you have large birds, the cages are usually very large also and it can be difficult to cover a cage that is taller than you are.
Some birds will chew a cover, but this is apt to be a bird that is only sometimes covered or is still covered when past his normal wake up time.
Putting a cover over a cage because the bird is being noisy during the daytime is not acceptable. Birds can be noisy and there are better ways to deal with the noise than to try to silence him this way. Any time that I have heard of someone doing this to a bird, it is usually shortly before they have decided to find another home for this poor bird because the problem seems to get worse being dealt with in this manner. Cage covers are for night time use or for travel use only.
The only time I cover my Congo African Grey, Jewel is when I am taking her someplace in her travel cage during the cold winter. If the weather is nice, I do not cover her at all.
What do you do? Do you cover your bird's cage? Let's talk about it in the forum.