Grasshoppers reared on black backgrounds survive by matching their environment. [causal]
Not only do such grasshoppers match their black environment, they prefer to settle on such backgrounds. It is obvious that grasshoppers with a conditional response to the environment in which they are reared are more likely to survive than those that are inflexible. They would also do better than those that go black on a probabilistic basis, matching the likelihood of becoming black to the probability of savannah fires. Clearly, many grasshoppers that go black probabilistically would do so at the wrong time and be highly conspicuous to predators as a result.
Diego Gambetta, Trust - Making and Breaking…, loc. 429