If you're using your MacBook as a replacement for a desktop computer, the trackpad quickly becomes cumbersome. It's great for occasional or practical use when you're on the road, but use it at home and a mouse will soon prove itself. You can configure Mac OS X to automatically disable the MacBook trackpad when using a mouse. Here's how.
You should only need to do this once because we configure Mac OS X to disable the trackpad whenever it detects a mouse. It will work the same for both wired and wireless mice. Since I work with the trackpad, I'll also show you how to invert it, just in case you prefer to work that way.

Disable MacBook Trackpad When Using a Mouse
Until something better comes along, a mouse is the best way to control any computer for the long haul. Spend a few hours on your MacBook and the trackpad quickly becomes very tedious to use. A good Apple mouse is comfortable for much longer periods of time and that's the way to work I think.
To disable the MacBook trackpad when using a mouse:
Select the Apple logo in the top left, then System Preferences.

Select Accessibility, then Mouse & Trackpad.

Check the box next to "Ignore built-in trackpad when wireless mouse or trackpad is present".

Now when you connect a mouse to your MacBook, macOS X will automatically disable the trackpad until you remove the mouse. I now know why this setting isn't under mouse or trackpad, but it is there.
Invert MacBook Trackpad
Since "Natural Scrolling" was introduced in the days of Lion, I had to invert the trackpad. I use both Apple and Windows and leaving natural scrolling on means I not only have to switch OS in my little brain, but I also have to scroll in a different direction. Only Apple users might not have a problem, but IT techs like me do.
Luckily, you can reverse the setting to make it work a little more like other OSes.
Select the Apple logo in the top left, then System Preferences.
Select Trackpad and Scroll and Zoom.

Uncheck the box next to "Scroll direction: natural" at the top of the window.

Now when you scroll towards you on the trackpad, the screen scrolls down. Scroll, the screen scrolls up.
Activate mouse keys
Another macOS feature is called Mouse Keys. The ability to move your cursor with the numeric keypad or the keyboard without the trackpad. This is a great backup feature if you are unable to use your trackpad.

To enable Mouse Keys, follow the instructions above to access "System Preferences". Click Mouse & Trackpad, then check the box at the top labeled "Enable Mouse Keys."

You can click the "Option" button to manage the feature and customize it according to your needs. When Mouse Keys is enabled, your keyboard will not work for text. To quickly disable the feature, use the keyboard to click Option, Command, and F5.
MacBook Trackpad Troubleshooting
If your MacBook trackpad isn't working or stops working properly for some reason, there are some basic troubleshooting tips that might get it working again.

Restart your MacBook
A full restart is always the first thing I suggest doing on any computer to fix a software problem. A multitude of errors can occur when an operating system is loaded and running and a reboot can fix most of them.
Unplug any mice you have connected, restart your MacBook, and try again. Chances are that if nothing is broken, the trackpad will now work normally.
Check for system updates
System updates also include firmware and driver updates that can fix all sorts of issues. If a reboot didn't fix the trackpad, make sure your operating system is fully up to date and running the latest drivers.
Go to the App Store or look for update notifications on desktop. Check for updates manually if you don't see an alert.
Check trackpad settings
If you made any of the changes listed above to disable the trackpad or to use a mouse, make sure the mouse has been disconnected and/or disable the setting. It's easy to forget to turn off a Bluetooth mouse or unplug a wired mouse.
Review the settings above and uncheck the box next to "Ignore built-in trackpad when wireless mouse or trackpad is present". Test the trackpad again and try another restart just in case.
Delete property list
Deleting the property list files is a last resort step, but if nothing else has worked, you might not have a choice. Property list files are a collection of user settings that control how your MacBook works. Any customizations you make are stored here, including input and trackpad. Deleting them without saving will return many of these customizations to default, so save first.
Use Time Machine to perform a system backup. Then navigate to /Library/Preferences. Delete the following files from the Preferences folder:
- apple.AppleMultitouchTrackpad.plist
- apple.driver.AppleBluetoothMultitouch.trackpad.plist
- apple.driver.AppleBluetoothMultitouch.mouse.plist
- apple.driver.AppleHIDMouse.plist
- apple.preference.trackpad.plist
Once removed, restart your MacBook and test again. If it was a wrong setting or an error, your trackpad should now work normally again.
If you need to disable the MacBook trackpad, now you know how to do it. Got any other trackpad tips or tricks we should know about? Tell us about them below if you do!