Hi, unfortunately with this motors you can't. They need something like 200mA and an arduino IO pin can give maximum 40mA. You can do it with the servos because they have s, +and -. SIGNAL (s) is only a control and doesn't require so much current. Learn how to use a motor shield can be really useful for a lot of projects, so I suggest to use one, the adafruit v1 is enough, it's cheap but allow you to control many motors without current problems.