Why do magicians avoid animal pro ducts for clothing based on the book red pyramid?

In "The Red Pyramid" by Rick Riordan, magicians avoid animal products for clothing because such materials can attract unwanted attention from magical creatures and forces. Wearing animal products might also invoke the spirits of the animals, which can lead to complications during magical practices. Additionally, using synthetic or non-animal materials aligns with the ethical considerations of respecting the natural world and its inhabitants.