"Living like Weasels" is an excerpt from Dillard's book Pilgrim at Tinker Creek. As a stand-alone piece, it functions as a familiar essay. A familiar essay is an essay that combines both factual, researched information with personal anecdotes and reflection.
Most of the essay is personal anecdote and reflection revolving around Dillard's mystical encounter with a weasel. However, she opens the piece with factual information and stories about weasels. These facts and anecdotes impress on the reader's mind the fierceness and relentless determination of the weasel. By offering us this information first, Dillard sets us up to understand why she is so moved by her encounter with this particular animal.
The essay is carefully structured into two parts: the first, short part of facts about weasels and the second longer and much more personal part about her meeting with one. A pivot sentence divides the two parts of the essay:
I have been thinking about weasels because I saw one last week. I startled a weasel who startled me, and we exchanged a long glance.
The story is carefully structured to maximize the impact of Dillard's communion with a weasel.