托福口语 Task 4

Today we're going to talk about a fascinating concept in animal behavior called 'safety in numbers.' This idea suggests that animals often gather in groups not just for hunting or social reasons, but primarily to reduce their individual risk of being attacked by predators. The more eyes watching for danger, the earlier a threat can be detected, and the more confusing it is for a predator to single out one target. Let me give you two clear examples from the wild. First, consider the sardine. When a sardine school is attacked by a tuna, the sardines do not scatter in panic. Instead, they pack together tightly into a massive, swirling bait ball. This dense formation makes it very difficult for the tuna to isolate and catch a single fish, as the constantly moving mass confuses the predator's visual tracking. Second, think about the meerkat. Meerkats live in mobs of up to thirty individuals. While they forage for insects, one or more meerkats will stand on their hind legs on a high vantage point, acting as sentinels. They scan the horizon for eagles or jackals. When a sentinel gives a specific alarm call, the whole mob instantly dives into their burrows, dramatically increasing the survival chance for each member. So, in both cases, group living provides a direct defensive advantage.