It is considered ‘wrong’ to kill another human being and it is ‘wrong’ to steal a towel from a hotel.
These 2 can’t possibly be equal so ‘sins’ must be weighed differently? 
Conscious acts are weighed more heavily than unconscious acts. Either can result in some suffering non the less but with the appropriate karmic effect. Reap what you sow.
Did you know that there are 8.4 billion life forms on earth?
But only human beings are capable of distinguishing right from wrong. Animals are exempt from the karmic justice and don’t create new karma and don’t affect their future destiny. All sentient beings can feel effects of karma though, be it pleasure or pain.

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