Sorry I forgot that fixing this behavior has changed - not sure which version or OS - but now:
In Photoshop go Edit > Keyboard Shortcuts, go to View, and change the shortcut for Extras to Cmd-H.
You'll get a warning that this changes an OS shortcut which is fine (I think the OS shortcut changes to Cmd-Ctrl-H). You may need to quit Photoshop and relaunch, but Cmd-H will hide marching ants after that.
Otherwise you can continue to use Cmd-Ctl-H to hide selections.