They were portrayed by a group of real life dwarves
Like the 1939 movie, some Munchkins do indeed speak in rather high pitched mousy voices and some speak in deep low voices. Despite their vocal differences the Munchkins in general are not at all harmful but, in fact, gentle people who are not violent but are easily intimidated when challenged by anything bigger than them. Because of this the Munchkins usually keep to themselves, not bothering anyone else outside their own country or causing other Ozians trouble. They are naturally very humble, happy little people who work hard to make a profitable, honest and decent living in Oz and love the simpler things in life such as the great out back of the Munchkin Country. A good majority of the Munchkin people are all gifted farmers who have large families. The Munchkins all live side by side with their neighbors, and treat each other like family, always being loyal to thy neighbor and are glad to help one another if ever in need. The Munchkins mainly raise richly abundant crops and successful vegetable gardens and are known as some of the most talented people in Oz when it comes to growing crops as farming runs in their Munchkin blood. Therefore the Munchkins are naturally born with "green thumbs". Most of them own their own land which they turn into large fields of stocks that stretch out for many miles across the land.