You know they're tiny, adorable and popular with the citizens of fictional Pawnee, Ind., but here are some things you might still be wondering about miniature horses.

1. HOW LONG HAVE THEY BEEN AROUND?

Despite some persistent myths to the contrary, mini horses are not directly related to the ancient eohippus, which stood just 1 to 2 feet tall. Those, and other prehistoric precursors to the horse, have been extinct for many millions of years. Instead, the modern miniature horse was specifically bred for its size several times throughout history, with the first known example dating to the 1650s when King Louis XIV of France kept mini horses in his menagerie at Versailles. In other instances, the smallest horses have been bred to one another for the sake of creating circus novelties, workhorses for the narrow mines of both England and America, and most recently as popular pets.

The first recorded mention of a mini in America came in 1888, when a lone mini measuring just 31 inches tall at the withers (the top of the shoulder) was discovered amongst a heard of Shetland ponies. He was given the name Yum Yum.

2. WHAT CONSTITUTES A "MINI" HORSE, AND WHY AREN'T THEY "PONIES" RATHER THAN "HORSES"? 

Technically, any member of Equus caballus under 14 hands 2 inches (a hand is four inches) is classified as a pony. But because most minis display a typical horse phenotype with physical features like longer, thinner legs, they are classified as horses and not ponies. The height cutoff for a mini is 38 inches for the American Miniature Horse Association (AMHA) and 34 inches for the American Miniature Horse Registry (AMHR). Anything taller than 38 inches is a Shetland pony. And at exactly 38 inches? He can be registered in both AMHR and American Shetland Pony Club (ASPC).

There is no bottom limit for their size, although many of the most extreme examples have their growth stunted by a form of dwarfism that can cause significant medical complications. The smallest living horse, as recognized by the Guinness Book of World Records in 2006, is Thumbelina, a miniature sorrel brown mare from St. Louis, Mo. who measures 17.5 inches.

3. WHAT ARE SOME ADVANTAGES TO THEIR VERTICALLY-CHALLENGED STATURE?

Just like smaller dogs tend to live longer than larger breeds, mini horses, on average, outlive their normal-sized brethren. Their average lifespan is around 30 years old, and the oldest known mini was a dwarf named Angel, who was just under 2 feet tall and lived to be over 50. Plus, they need less food and require less space than normal-sized horses.

4. WHAT DO PEOPLE DO WITH MINI HORSES?

iStock

Plenty of people keep them as pets. They can't be ridden by anyone except a small child, but they are able to pull carts and buggies with adult drivers.

Because of their compact size, mini horses are potential candidates for serving as guide animals. In addition to appealing to horse-lovers, using minis in place of dogs has several benefits, including their longer life spans, which means they can serve as a guide and companion for over 30 years. Not every mini has what it takes to be a guide horse, however. Even before training can begin, the horses must pass an intelligence test to ensure that they have potential.

Other minis have found work as volunteers in the Los Angeles County Sheriff's Department. There are several horses owned and employed by the Sheriff’s Department, where their job is to accompany officers to events at schools and libraries to help ease the introduction of law enforcement to children. Another popular use for minis is to visit hospitals as a therapy animal.

5. AND WHAT ABOUT LI'L SEBASTIAN FROM PARKS AND RECREATION? WHAT'S HIS DEAL?

Unlike many animal roles, Li'l Sebastian was played by a single miniature horse named Gideon, who has also appeared in Hart of Dixie, Daddy Day Care and a slew of commercials. When he's not working, he lives on a 150-acre ranch in Piru, Calif. Gideon's trainer, Morgan Bateman of A-List Animals, still has the eulogy and funeral pamphlet—full of actual Li'l Sebastian trivia—following the fictional horse's memorial service. Now, Gideon's living on a ranch with other movie horses, waiting for another call from Hollywood.