Answer: She means a weasel lives it's life as it should
Explanation: When Dillard writes a weasel lives it's life as it should she means that the weasel stays in it's place lives where and how it's supposed to live and does it's best not to interfere with other life forms. She is saying that the weasel lives it's life and doesn't make it any harder for anyone
"A weasel doesn't “attack” anything; a weasel lives as he's meant to...”
Dillard uses the weasel metaphor to defend how it is important that every person find what he/she feels the need to do in life and that they stick with it.
All of them: this is how the title of the poem is in original (well, this is how Neruda named it in Spanish) - the title is part of the Poem, and should be kept in its original form.