This is the 2333rd most frequent Polish word.
wracają
"Wracają" means "they return" or "they are returning."
Here, 'wracają' is the third person plural form of the verb 'wracać', meaning 'to return'. It indicates that the students are coming back to a location they previously left.
Uczniowie wracają do szkoły po wakacjach.
The students return to school after the holidays.
In this context, 'wracają' refers to birds migrating back to their habitat during spring.
Ptaki wracają na wiosnę z ciepłych krajów.
The birds return in spring from warm countries.
Here, 'wracają' is used metaphorically to signify the act of mentally revisiting past times.