They are what cheddar is before being formed into blocks and aged. Cheddar cheese is typically aged from 60 days to 4 years before being sold, whereas cheese curds are eaten straight away. While you can find mozzarella cheese curds, or other types of cheeses, it's almost always cheddar.
Players are signed and can be as young as 16. International players must be 16 to sign a contract. The universal age a player must be to play major league baseball is 16. The age limit is literally limitless. Once you get your high schooling it goes from there and you can be in the MLB which is usually around 18 for most people.
Confidence votes 12. The average age of a rookie in Major League Baseball during the 2000s has been approximately 24 years old. According to a story in the New York Times dated September 4, 2005, the average for that year was 24.2, the same as it had been in 1991, 1952, 1948, 1938, 1928 and even 1903.