When Bacca was 9 months old, I had enough of his constant herding me....so I decided to get another dog to for him to herd.....Worked like a charm! But I still crated them both until they were almost 2 years old.
Seriously though, this behaviour can go go on for many months yet. With my first Sheltie, Timber.....I thought he was well past the chewing phase at 18 months.....then he decided to chew holes in my brand new living room couches.
All to say, don't let your guard down yet!