Hogwarts he is detected using magic in the presence of Muggles, a serious offence among the wizarding community. Dumbledore argued in Harry's defence, stating that it was done in self-defence, and that the Ministry has no authority to expel students – such powers are invested in the Headmaster and the Board of Governors. Snape has attempted to have Harry expelled, and he attempted to have Harry's father, James Potter, expelled when they were at Hogwarts together. The only student known to have been expelled is Hagrid, for the murder of Myrtle with an acromantula believed to be the Monster of Slytherin
Hogwarts of course." According to the novels, admission to Hogwarts is selective, in that children who show magical ability will automatically gain a place, and squibs cannot attend the school as students (though they can work there in other roles, as Argus Filch does). A magical quill at Hogwarts detects the birth of magical children and writes their names into a large parchment book, but there is no admission test because "you are either magical or you are not." Every year, a teacher checks this book and sends a letter to the children who are turning eleven. Acceptance or refusal of