Human-presence-revealing Spell

Homenum Revelio is the incantation to reveal human presences in a building or place. Hermione Granger used this spell in Harry Potter and the Deathly Hallows to search for any hiding people (or Death Eaters) in Number 12, Grimmald Place after they escaped persuing Death Eaters. A Death Eater had used this spell to attempt to locate Harry Potter on Xenophilius Lovegood's house. Detected persons apparently feel a strange sensation upon detection.