Apple - Disable Trackpad and Keyboard Temporarily

For the trackpad, there’s a setting for this on 10.7 and later.

System Preferences > Accessibility > Mouse & Trackpad > “Ignore built-in trackpad when mouse or wireless trackpad is present”

As for the keyboard: I haven’t tested this solution for disabling the built-in keyboard and wouldn’t recommend doing it either. Apparently you can unload a kernel extension to disable it completely.

Before doing this.....

WARNING: Before disabling the built-in keyboard, make darn sure you have an external keyboard connected!!

WARNING: Before disabling the built-in trackpad, make sure you have an external mouse connected!

 sudo kextunload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTCKeyboard.kext/ 

To enable it use external keyboard...

sudo kextload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTCKeyboard.kext/ 

Source: http://t3chnot3s.blogspot.com/2013/12/disabling-built-in-keyboard-and.html

However I would recommend a simple and safe and very temporary method is to cut a piece of cardboard and place it on top of the keyboard. It worked for me to prevent my Cat taking over.