Hogwarts schooling

You set a mental alarm against unwanted intrusion. Choose a door, a window, or an area within range that is no larger than a 20-foot cube. Until the spell ends, a ping in your mind alerts you whenever a Tiny or larger creature touches or enters the warded area, if you are within 1 mile of the warded area. This ping awakens you if you are sleeping. When you cast the spell, you can designate creatures that won't set off the alarm.