Final answer:
Animals must respond to predators using the fight-or-flight response and through communication methods like aural or chemical signals to survive. These adaptations are crucial for avoiding predation and differ among species.
Step-by-step explanation:
A normal animal must respond to the sight and sound of a beast of prey as part of a survival mechanism ingrained in their nervous system, known as the fight-or-flight response. This response is critical for the survival of prey animals, as it allows them to quickly flee from potential threats, thereby reducing the likelihood of predation. Birds, for example, utilize various methods to communicate the presence of predators, such as releasing chemical compounds, making aural signals, or using tactile signals. These methods serve as warning systems to other birds in the vicinity. Additionally, adaptations in an animal's sensory system—like a good sense of hearing selected for nocturnal animals—help them detect predators early and respond appropriately.