What social distancing does to a fish brain. Researchers have discovered a brain molecule that functions as a 'thermometer' for the presence of others in an animal's environment. Zebrafish 'feel' the presence of others via mechanosensation and water movements -- which turns the brain hormone on. Source 1s.
As humans I think we've grown so accustomed to the way we communicate that we don't realize that there are so many other forms of communication taking place.