Why are there so many birds chirping outside the window when it is cold? Isn't it cold, they? Are their nests frost-proof?

You should know that birds do not come out for fun, but to find food to meet the needs of their own life activities. In other words, whether it is windy or rainy or cold, birds will come out. Don't think about birds with your own psychology.

As for whether the bird is cold or not, I'm afraid I have to ask the bird itself, but the bird's feathers are very thick and probably not too cold-just think about how warm it is to wear a down jacket. The filler of the down jacket is the bird's feathers. In order to ensure safety, the bird's nest will also be built in a sheltered place. Although they are certainly not frost-proof, they can more or less reduce the harm caused by cold to themselves and their children. Because the warmth retention of most birds will decrease after their feathers get wet, it will also affect their flight ability, so the activity of birds will decrease in rainy and snowy weather, but birds will be more active than before after the weather clears up.

Please adopt it if it is useful.