Things that go bump in the night

In the book there is a part where a girl name Emma, who lives in a apartment on the top floor, who room is next to a window with a gargoyle in the corner of the apartment, was about to go to bed, but then she heard a noise, like a nail scraping across a chalked board, outside her window. So I'm thinking that a creature with long nails is trying to get inside the apartment by going through the window.