woofgang replied, to a duplicate question: "Well you have introduced another member to the pack and the pack is sorting itself out. In some dog breeds, a strong pack boss (you) can enforce subordinacy on the rest of the pack and validate their pecking order choices. This sounds quite nasty, it means that you decide who you allow to greet you first, (should be the most dominant dog) be fed first, get the warmest sleeping place etc, then next in line and so on and ENFORCE it, punishing any dog who dares to try and usurp anothers place. problem is that humans have a "fairer" view of family life and find this difficult, tending to prefer the underdog. Take a look at a book called the dog whisperer for further info."