Fools and dead flies both cause good things to stink. As a metaphor, it falls a little flat. Wise men's hearts swing right, fools' left. I kind of like mine in my chest. If your ruler gets angry, stay calm and he'll simmer down. I actually find that there is nothing more maddening than a person who stays cool when I'm all het up.
If you dig a pit, you'll fall in and if you break through a hedgerow, a snake will bite you. Removing stones will result in one falling on you and if you chop wood you'll invariably lose a hand or something. It's like a really depressing Murphy's Law.
Snakes sometimes bite the charmer before he's done his bit. Woe betide the land ruled by a boy king and whose princes enjoy all-you-can-eat brunch buffets. Much better to have a noble king and princes that eat at the appropriate time. You know, I live in a country where the vast majority of the people eat the following for breakfast: one extremely thin slice of ham on bread, and another extremely thin slice of cheese on bread, all washed down with coffee. Then they have the same for lunch. Four sandwiches a day, none of them buttered. And they don't rule the world.
Don't curse the king or the rich, even in the privacy of your bedroom because you never know what the walls will overhear.