If he is an only furchild he may never dook.  I had a little girl for a
year and thought she was mute until I got her a playmate.  Turns out she
was very vocal, just had nothing to say to us!  Also, I have a year old boy
that I've had for six months.  I thought he didn't make sounds either until
I saw him trying to get one of my older ferrets to play and then he was
just chattering his little head off.
 
Laurel
[Posted in FML issue 3497]