Should collapsed left column flyout menus show on hover or click?

I have a left column within my app that houses my main navigation. I have the ability to collapse that column, which creates a compressed version of the menu showing icons only. What is the standard for showing the submenus? Should they show on hover or click?

I was leaning to showing on click since the rest of my app is all click to show any menu. Is there a standard for this?

Expanded Version

Collapsed Version