For security reasons, Snowfox comes with a feature, which allows phone calls only from a set of separately allowed numbers. This set includes only the users in Snowfox Family mobile application; the main user who took the service in use and separately added guardians.
If the user disables his/hers caller ID, the service can't recognize the caller. In this case the phone call is automatically disconnected before it alarms the Snowfox device.
You can get more information about enabling the caller ID from your phone's manual or from your mobile operator.