Any baby equine (horse, donkey, mule or zebra) is called a foal. Male foals are colts (or Jack foals in the case of donkeys), females are fillies (or jennet foals). They are grouped as “Foals” up until they are weaned, usually about 6-8 months old, then they are Weanlings. After their firstbirthday, they are Yearlings. They may still be called Colts or Fillies up until they are mature, usually at 3-4 years of age. Breeding males are stallions (horse or zebra) or jacks (donkeys or wild asses). Females are mares (horses, zebras, mules) or jennets/jennies (donkeys or wild asses). Male mules should NEVER be left intact, so stallion mule or jack mule should never be used. Male mules should be gelded before age 2 and are called Horse mules, geldings, or sometimes “johns”.