Most food chains have no more than four or five links. There cannot be too many links in a single food chain because the animals at the end of the chain would not get enough food  to stay alive.

Most animals are part of more than one food chain and eat more than one kind of food in order to meet their food and energy requirements. These interconnected food chains form a food web.

A change in the size of one population in a food chain will affect other populations. 

This interdependence of the populations within a food chain helps to maintain the balance of plants and animal populations within a community.  For example, when there are too many giraffes; there will be insufficient trees and shrubs for all of them to eat.  Many giraffes will starve and die. Less giraffe means more time for the trees and shrubs to grow.

Eagle

Owl

Snake

Rabbit

Mouse

Frog

Grasshopper

Clover

Wheat