Given a scientific passage and an answer, generate a question for the given answer.

Let me give you an example: Passage: A frameshift mutation is a deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence. Deletions remove nucleotides, and insertions add nucleotides. Consider the following sequence of bases in RNA:. Answer: nucleotides.
The answer to this example can be: A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?
Here is why: The science passage defines frame mutation and the main compoment here is nucleotides. Hence the generated question is apt.

OK. solve this:
Passage: Many species use their body shape and coloration to avoid being detected by predators. The tropical walking stick is an insect with the coloration and body shape of a twig, which makes it very hard to see when it is stationary against a background of real twigs (Figure 19.15a). In another example, the chameleon can change its color to match its surroundings (Figure 19.15b). Answer: predators
Answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Many species use their body shape and coloration to avoid being detected by what?