The professor uses two examples to explain the ways animals use to protect their foods. Firstly, some animals can cultivate plants. there is a kind of fish which can cultivate their favorite sea weed, by biting other plants which can block the sunshine to the seaweed. Secondly, some other animals can raise other animal species as their food resources. Black ants take care of a kind of small insect, they even raise these insects' eggs and youth for the insects can produce sweet liquid which can feed the ants.
The professor uses two examples to explain the ways animals use to protect their foods. Firstly, some animals can cultivate plants. there is a kind of fish which can cultivate their favorite sea weed, by biting other plants which can block the sunshine to the seaweed. Secondly, some other animals can raise other animal species as their food resources. Black ants take care of a kind of small insect, they even raise these insects' eggs and youth for the insects can produce sweet liquid which can feed the ants.