Teething At 9 Months Old?

[Bob's mum]

Hi,
This might be a really silly question, but do 9 month old pups go through another teething stage??
Bob has been off his kibble for 2 days and is spending a lot of time with his nylabone, which he has never even looked at before!!
He is still eating his chicken wings though-so i am not worried he is ill. i just wondered why he has suddenly gone for his nylabone???