Duplicate photos on Android phones can be caused by several factors. One possible reason is when the phone's camera settings are configured to save both the original and edited versions of a photo. Other causes may include file transfer errors, corrupted files, software glitches, or third-party applications that create duplicate copies of photos. To address this issue, users can employ several methods, including using apps specifically designed to find and remove duplicate photos, manually deleting duplicate files, or syncing their photo library with cloud storage services to avoid data loss when deleting duplicate files. It's essential to regularly clean up your phone's photo library to free up storage space and avoid clutter.