Ferrets were not discovered as they do not exist in the wild. They came about after someone, at some point in time in an unknown place, realized that a trained polecat would be an invaluable aid in the hunting of rabbits due to rabbits being the polecat's natural prey and also because polecats are extremely agile creatures that are more than capable of following a rabbit down a burrow.
Once a wild polecat - probably a bay one, as it'd be easier to domesticate and train - had been obtained and the experiment proved successful, it would have made sense to breed more rather than have to go out and catch them. Over time, these domesticated polecats became known by a different name - ferrets.
The point at which people first began to keep ferrets as pets, rather than as working animals, is also unknown. However, we are not so very different from people thousands of years ago and it's probably safe to assume that various people simply liked ferrets enough to keep them as companion animals.
Black footed ferrets where discovered by John Audubon and James Bachman in 1851
Ferrets are only bred with other ferrets
The collective term for a group of ferrets is a "a business of ferrets" or "a cast of ferrets".
Weasels and their kin, ferrets, stoats, ermine etc have been known since at least the days of the Roman Empire. An exact date of discovery is unknown, but they have been classified taxonomically for at least 300 years.
Panda ferrets the same as other ferrets, just the coloring is different.
Ferrets do not hibernate.
Ferrets do have a ribcage
The plural for ferret is ferrets but a group of ferrets is called a "business" of ferrets.
Wild ferrets - European polecat ferrets live in Europe. Black Footed ferrets live in North America.
Domestic ferrets have lost all natural instincts to survive on their own in the wild and would probably starve to death if not killed by a predator first.
They can get along, but they don't get along as well as two male ferrets. Female ferrets, after they get spayed, are much more territorial than before they get spayed. If you are thinking of getting two ferrets, I suggest getting one male and one female. Of course, you should get them spayed and neutered, first.
Ferrets are not dangerous at all