I'm not sure if I can trust a random article on the internet but I do (mostly) trust my eyes. I have lots of small bird-feet-tracks outside my window where they

I'm not sure if I can trust a random article on the internet but I do (mostly) trust my eyes. I have lots of small bird-feet-tracks outside my window where they have melted the snow. So clearly either they are not freezing because they are warm or they are covered in anti-freeze.