The words micks, mix sound the same but have different meanings and spellings. Why do micks, mix sound the same even though they are completely different words?
The answer is simple: micks, mix are homophones of the English language.
To combine or blend into one mass or mixture.
To create or form by combining ingredients: mix a drink; mix cement.
To add (an ingredient or element) to another: mix an egg into batter.
To combine or join: mix joy with sorrow.
Definitions , from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.
If they are spelled the same then they are also homographs (and homonyms); if they are spelled differently then they are also heterographs (literally "different writing").