In Chapter 3, what has the reader learned about Dillard's attitude towards living creatures?

The reader knows that Dillard seems to have forsworn harming any living thing because of her experience with the beetle as a child. She not only declines to collect or harm living creatures, but she aids their survival, as evidenced by her story about leaving the towel hung over the tub so that spiders can climb out. One contradiction in her personality, though, occurs later in the book. Dillard, after examining pond water under a microscope, throws the water out, even though she can see that there is life (amoebas) in the water. Is there a point where Dillard thinks life is no longer valuable?