青蛙不仅吃蚊子、苍蝇等小昆虫,还大量捕食飞蛾、稻飞虱等农业害虫。一只青蛙一年可以消灭5万多只害虫,真不愧是“捕虫能手”。夏天的晚上,人们时常可以看到这样的情景:一只青蛙蹲坐在池塘边上,一动不动、目不转睛地盯着迎面飞来的各种小虫子。忽然,它腾身跃起,伸出像鞭子一样的舌头,准确无误地把虫子卷进嘴巴里。更有意思的是,青蛙每次吞咽食物的时候都会眨眼睛,吞咽的食物越大,眨眼睛的次数也就越多,直到把这些食物全部吞下去为止。这又是为什么呢? Frogs not only eat mosquitoes, flies and other small insects, but also a large number of predatory moths, planthoppers and other agricultural pests. A frog can destroy more than 50,000 pests a year, really worthy of “insect catcher”. On the evenings of summer, people often see such a scene: a frog sitting on the edge of the pond, motionless, intently staring at the various small bugs coming in. Suddenly, it leaped forward, sticking out its tongue like a whip, and rolled it into the mouth with accuracy. Even more interesting is that the frog blinks every time it swallows food, the more food it swallows, the more blinking its eyes until all of it is swallowed. This is why?