I have Yorkie brothers, different litters, less than a year apart. They have different personalities and different looks (although neighbors can't tell the difference), but they also have a lot in common. I often wonder if they sense they are related. Max recognized his breeder when we picked up Teddy, so I think he understood that his new brother came from the same place.
Although Max was instantly fascinated with Teddy and accepted him, we had some jealousy issues to work out over time. Now they share everything.
