An apparatus is provided for discouraging a user from sucking on their thumb. The apparatus of one example includes a hollow vacuum-breaking device (10), a pair of straps (26) extending from the vacuum-breaking device, and a retainer (30). The vacuum-breaking device is sized to permit insertion of the users digit into the vacuum-breaking device so that its base is nearer to the base of the thumb, with its air passages preventing the user from establishing a sucking vacuum when the respective digit including the vacuum-breaking device is inserted into the users mouth. The pair of straps defines a pair of holes, and the retainer is configured to extend through overlapping holes of the straps to thereby secure the straps together. The retainer defines an aperture for receiving a wristband (32) securable to the users wrist to secure the straps to the users wrist, with the vacuum-breaking device thereby being securable to the users hand.
