Since the iPhone 5S was released this week, its TouchID fingerprint unlocking system has been the most talked-about feature. While we’re all contemplating the implications of a database of iPhone users’ fingerprints, people have been trying to unlock the phone in other creative ways. A cat’s paw can unlock the screen, as can other parts of the human anatomy.

The experiment continues via Japan’s RocketNews: A man has apparently locked and then unlocked an iPhone 5S with his nipple. When a different nipple attempted entry, it was denied.

But wait, there’s more! If the iPhone recognizes a nipple, might it also recognize a toe?

Ah, science. No word on whether women's nipples also unlock the phone, but it never hurts to try. One thing’s for certain: These new devices are getting to know us very intimately.

Screengrab via RocketNews24/YouTube