'Karma' and 'food-chain'

Karma and food chain work on the same principle I guess. Citing an example if a food chain :
A grass hopper eats grass,then the grass hopper is eaten by a frog,followed by a snake eating the grasshopper and finally the snake being the target of an eagle.
Similarly , we are free to involve ourselves in good or bad deeds but we are not free from its consequences. We are rewarded for our good deeds and penalised for our wrong doings.One cannot escape from the karma he or she does.sooner or later we have to reap the fruits of the seeds sown by us in the past.
I believe, we should learn to empathise.If we cant be good to people we have no right to be bad to them.