To perform some actions on a Mac computer, it is more convenient to work with the mouse than with the built-in trackpad. At this time, a huge touch pad under the keyboard often captures false presses, shifts the cursor, or works off unnecessary gestures.
You can disable the built-in trackpad while working with the connected mouse.
How to set the trackpad off
1. Go to System Settings – Universal Access .
2. In the Mouse and trackpad section, activate the flag Ignore the built-in trackpad in the presence of a mouse or a wireless trackpad .
Now, after connecting a mouse or wireless trackpad to your MacBook, the built-in touchpad will be turned off so as not to fix false clicks and accidental hits.