Answer:
I have four wings but cannot fly. I never laugh and never cry. On the same spot always found, toiling away with little sound.
Only one color, but not one size. Stuck at the bottom, yet easily flies. Present in sun, but not in rain. Doing no harm, and feeling no pain.
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
Hold these between your knees if you want to set a Cuban beat.
What can be seen but never found that only hides in the unwound?
Strip the skin under my skin, and my flesh you'll reveal. It tastes sweet and tart, now throw out the peel. What is it?