The Moto G runs Android KitKat or later versions. USB mass storage (UMS) has been removed from these versions of Android. So, plugging in a USB thumb drive or a hard disk of any kind is not possible.
You could use FTP to transfer files over wireless. Or use the slow MTP or PTP to transfer files by connecting Moto G to a computer.
Tried with: Android 4.4.3 and Moto G
Tagged: ftp, moto g, mtp, ptp, usb mass storage
