So that the reader understand how they lived.
In chapter 11, Mrs. Tibbits and Ben just get back from toad watching because it was raining. Mrs. Tibbits tells Ben the reason why her sister-in-law wants to sell the house. Developers want to purchase the property to build on it. Ben realizes this is not good because the Spadefoot toads are endangered and if developers indeed purchase the property and build there, the spadefoot toads will no longer be able to lay their eggs and will probably become extinct. Ben is trying to hatch a plan to help Mrs. Tibbits in this situation.
Rhetoric is the art of persuasive speaking or writing.
