How does the sparrow overwinter

The sparrow usually finds a tree hole, and its own feathers will become fluffy, so that it can keep warm, thereby spending winter.There are many types of birds, and the size and body color are very close, and the distribution is very wide.They are mostly active in the place where humans live. They are more lively and courageous, but they are also very vigilant. They usually eat grain seeds and eat insects.