生物和生物之间,在自然界常常形成利害相关的生存关系。蚜虫吃植物,瓢虫吃蚜虫,山雀吃瓢虫,老鹰吃山雀。这是一种斗争的方式,也就是人们常说的“食物链”。还有另一种方式,两种生物和睦地生活在一起,彼此有利,或者对一方有利、对他方无害。这就是生物的共栖和共生现象。 Between organisms and creatures, often in the nature of the formation of stakeholder relations. Aphids eat plants, ladybugs eat aphids, tits eat ladybugs, eagles eat tits. This is a way of struggle, which is often referred to as the “food chain.” There is another way that both creatures live in harmony, good for one another, good for one, and harmless for the other. This is the phenomenon of biological cohabitation and symbiosis.