Servos are great when building a robot and you want to be able to rotate back and forth like you’re looking for something. You may have sensors that scout around for another robot and putting it on top of a servo provides that mobility. Servos are also very useful when building a robotic arm and many other things.
One problem you’ll run into is wires that aren’t long enough to reach from your controller to the servos. That is when you need servo extensions.
This Instructable page for DIY Servo Extensions will lead you through the process of making your own servo extensions.