What is a young horse, usually less than six months old, called?

A young horse that is typically less than six months old is referred to as a foal. This term is specifically used to describe a horse during its early developmental stage, from birth until it is weaned. Foals are dependent on their mothers for nutrition and care, and this period is crucial for their growth and socialization.

The other terms have specific meanings that apply when the horse is older. A weanling, for instance, is a horse that has been weaned off its mother's milk, typically around six months of age, marking a transition from the foal stage. Filly and colt refer to young female and male horses respectively, but these classifications generally apply to horses that are older than a foal, typically starting from around one year of age. Thus, the distinction of a foal as the correct term emphasizes both its age and developmental stage within the first few months of life.