Arduino Robotic Arm Problems

Currently, I am working on a robotic arm that uses the Arduino. It uses 5 servos, and for some reason it keeps jittering and I am not entirely sure as to why. Whenever we have one or two servos, it seems to work perfectly fine, but as soon as we hook up the other servos, the robot goes crazy and has a high amount of jitter. We are using a 9V battery that is hooked up to the breadboard, and the Arduino is connected to a computer. We have the Arduino and the potentiometers/servos grounded. I'm not really sure what the problem is, if anyone can offer some advice, that would be great. Thank you.

Your post raises several red flags about servo usage.

What 9v battery are you using? If it is a smoke detector style battery, then it is completely inadequate for powering servos (or much of anything)

Are your servos 9v capable? Or is the 9v being reduced through a voltage regulator? If so, which one? I HOPE it is not the 5v pin of the arduino. This cannot power multiple, loaded servos.

What servos are you using? Some servos draw a LOT of current. Even the smallest servos draw enough current that when put in multiples, can overwhelm an inadequate power supply.

Are you running servo power through the breadboard? That can be problematic. Breadboards are great for signal level current. Want to light up a few LEDs? Breadboards are your friend. But when it comes to powering the motors in servos, breadboard traces are too thin.
Especially if those servos are loaded.
Especially if there are multiple servos.

There are also physical design issues that might be overpowering any individual servo. How heavy is your arm? How long are the segments? Can you provide some pics?