Symbolism, Imagery, Allegory
Was it just us, or was there a lot of bug imagery in Cat's Cradle? Well, let's scour the book and see what we can sweep up:
• We are introduced to Frank shaking a jar full of insects during the day of the atomic bomb (6.7).
• Angela keeps her family photos in an album that reminds John of "beetles in amber" (52.3).
• Crosby mentions his daughter wanting to marry a man whom he "squashed [...] like a bug" (59.11-13).
• In fact, Crosby calls everyone he doesn't like a "pissant" (69.7).
• At the novel's conclusion, Frank experiments with an ant farm to discover how they learned to survive ice-nine (124.7).
As we can see, the insect imagery seems to revolve around certain characters. Characters like Julian Castle or Bokonon don't interact with insects or have insect terms used to describe them. So what are we to make of the characters that do?
To put it simply, characters like Frank and Crosby aren't exactly the humanist type. They don't see people so much as people but as things in the world for them to use. Crosby runs a bike company and only sees people as human resources or means of profit. Frank sees them as experiments or tools, something to play with.
As for Angela, her mind is wrapped around herself and her family. Her attempts to present her family in the best possible light amount to her preserving their memory rather than understanding who they are or were. She even demands of John to make her father a "saint" in his book since that's what he was—in her mind at least (51.21).
So, basically, if you want Vonnegut's approval—or at least Cat's Cradle's approval—make sure you avoid insects.