When they reach the end of the verse they stop, the single in the middle performs an action (such as Highland dancing), which everyone then imitates, before starting the verse again, often changing the single player to a boy, or a boy can join the center player - thus creating an extra verse in the song ("Did you ever see a laddie...").
When they reach the end of the verse, the single performer executes an action (such as Highland dancing), which everyone replicates before restarting the verse, often switching the solo player to a boy or a boy joining the center player - thus creating an additional verse in the song ("Did you ever see a laddie...").