見つける vs 見つかる

[Andromedashun]

I knew that both mean ''discover'', but can anyone classifield for me their usage.
For example you use かぎが見つかりました why not かぎが見つけました?

PS: My thought is that 見つかる is transitive and 見つける is intransitive, but I'm not sure.

 

[Toritoribe]

That's the contrary. 見つかる is intransitive and 見つける is transitive. Further, 見つかる is spontaneous and 見つける is volitional.

 

[Andromedashun]

Oh, that's something new to me. Thanks!