yorkshire terrier

Question
hi
 my yorkshire terrier bitch is 6 months old and has been mounting my yorkie dog over the past few days, why is this? is she due in sseason

Answer
Typically mounting and humping are not sexual acts but an act of dominance.  What she is trying to do is let your male know she's boss.  It's a trait that should be discouraged immediately as it gets worse as they age.

But that being said, at 6 months she could start her heat.  Check for swelling and bleeding to ensure she's not and keep her far away from your male if she is.  She is too young for her first breeding.

Good luck