A*STAR roboticists have created an autonomous shelf-scanning robot called AuRoSS that can tell which books are missing or out of place. Many libraries have already begun putting RFID tags on books, but these typically must be scanned with hand-held devices. AuRoSS uses a robotic arm and RFID scanner to catalogue book locations, and uses laser-guided navigation to wheel around unfamiliar bookshelves. AuRoSS can be programmed to scan the library shelves at night and instruct librarians how to get the books back in order when they arrive in the morning.