Do you have to give each of the mules its own name or do you just call them "Mule?" What if there is one on the couch and I want it to move? If I yell "Mule move!" will they all move? Are they easy to tell apart? I don't know if I can remember 20 names.
The correct form of address is "Git along Mule!" Please bear in mind their legendary intractability.