Betcha a combine would get them to move!
You know, if those really are students, you kind of have to admire their operational security to be able to spring this by surprise.
46 degrees there now. surround them, bring in a water truck with cold soapy water and spray them down. Then don’t let them leave. The soap will allow the cold water to go through their clothing.
That is how you get rid of starlings nesting in your trees.