Rennie barks at most of the things Shelties bark at---which is amost everythng, as others have said. But there are a few things that are particularly funny:
She barks entusiastically when...
... people applaud.
... a group of people sing "Happy Birthday." (She doesn't bark at choral singing generally, just at the song "Happy Birathday." I think it's because when we sing it for her birthday, she gets "cake.")
...she hears us say one of the "happy" words in her vocabulary--like walk, out, hike, tug, chase, breakfast, dinner, etc.
She barks fussily at...
...things that don't "belong" on the lawn--like a red gas can, left out after mowing, or a plastic bag caught in a shrub.
...animals on the TV that are vocalizing or running. (Of course those are things she barks at in real life, too. But oddly she doesn't bark at cars on TV.)
...her own reflection in the oven door.
She'll quiet if we tell her to: it is, after all, the Sheltie way to do what one is told to do, no? But mostly we let her speak her mind.
