what age to glue or tape ears?

Question
I have a 5 month old aussie pup and she has fully pricked ears. When we bought her her ears were folded and the parents ears were properly shaped. What age is appropriate to start ear setting? How long do I wait before the pricked ears are permanent? Thanks

Answer
If she has gone through the teething phase, you are probably already too late.  Were you planning to show this dog in the breed ring?  If so, you may want to read this: http://www.ashgi.org/articles/breeding_price_glory.htm
Aussies have a particularly small gene pool, and while many different ear sets are acceptable under the standard, not just the currently fashionable button set, prick ears are a fault and even if you tape for the ring, IMO it isn't really ethical to breed the bitch and possibly pass the trait along.