A flock of white pigeons flew across the sky at night and still screamed

It is the behavior of pigeons using pigeon whistles to court mates

There are many types of pigeon whistles, the materials are different, the load capacity of the pigeons themselves is different, the weather and wind are different, so the sounds they make are different.

This is a normal phenomenon. In addition, even male pigeons in a pair will call and track other pigeons. They will only be quiet when they are in the nest with their mates.