You click on an icon in the dock that brings up a grid of the items in the list and then you click on one of the items in that list. But I like the way the rest of the dock operates, where I know what I’m moused over (is moused the verb of mousy?). And I sometimes click on the wrong one, which is why it’s nice to highlight one. To do so, run this command:
defaults write com.apple.dock mouse-over-hilite-stack -boolean yes
And then:
killall Dock
To go back to the way things were before:
defaults write com.apple.dock mouse-over-hilite-stack -boolean no
And then:
killall Dock
