Inspired by Fred and George's example, a great number of students were now vying for the newly vacant positions of Troublemakers-in-Chief. In spite of the new door, somebody managed to slip a hairy-snouted Niffler into Umbridge's office, which promptly tore the place apart in its search for shiny objects, leapt on Umbridge when she entered and tried to gnaw the rings off her stubby fingers. Dungbombs and Stink Pellets were dropped so frequently in the corridors that it became the new fashion for students to perform Bubble-Head Charms on themselves before leaving lessons, which ensured them a supply of fresh air, even though it gave them all the peculiar appearance of wearing upside-down goldfish bowls on their heads.