For all purposes, hinnies are classified with mules. Hinnies do not differ from mules in endurance, or other useful traits, but are bred more rarely because the donkey dam tends to make the offspring smaller. Donkeys do not as readily conceive to horse stallion as to donkeys. The proper term for the male mule. All male mules should be gelded, since stallion mules are very sexually active, even though they are sterile.
Many people refer to a male mule as a john mule, but the term is informal.
The proper term for the female mule. The common informal term for the female mule is molly mule, and is frequently used. The terminology for the hinny follows that of the mule for clarity. The young male or female mule under the age of three. This is of course correct but more difficult to use in speech.