MacBook Pro Can't Find Serial Ports

I have just acquired a nearly new MacBook Pro, operating system 10.10.3. I downloaded the latest Arduino IDE, but when I activate the software and hook a Nano up to its single USB port, the Arduino list of ports never shows the attached Nano.

Anybody else have this problem, and any idea as to a remedy.

Thanks in advance for any tips.

Interesting update: The MacBook finds the serial port if a ProMini or a standard UNO is attached. Seems to be a Nano problem.

The Nano has an FTDI chip so you need to install the FTDI driver.
http://www.ftdichip.com/Drivers/VCP.htm

John,

Thanks very much. I'd been using Nanos on another MAC with no problems, but that one must have already had the driver installed.