I bet many people think birds sleep in their nest. In fact, they don't! They sleep in many different places but certainly not this one.
It is true that the image of a small bird sleeping in its nest after a hard day hunting is rather touching but it is mostly false.
Indeed, breeding birds only use their nest to protect their eggs and chicks. When the breeding season is over, the nests are abandoned. Most birds sleep in warm and safe places in the branches of a tree, behind the foliage on the ground or near water...
It is interesting that the majority of birds, unlike men, have their eyes connected to one half of the brain allowing them to sleep on one side of the brain and keep the other side conscious. Therefore, they can manage their degree of sleep based on the security of their location. For example, when ducks rest on a lake, those in the center are completely asleep while those near the sides of the lake are half awake. Some birds are even able to rest while flying!