Main Menu Dropdowns
Dropdown menus are great tools for navigation. There are a few steps to take within Drupal to make a menu behave as you want.
Editing the Menu
The Main Menu is hard-coded into the template, so it must be edited by going to Structure > Menus > Main Menu.
To ensure that a dropdown expands, edit the parent item.
Scroll down, and check off "Show as expanded."
The children will now always be available as a dropdown.