Because we are Ashraf-ul-makhlooqat means better from all creauters bcz we hv sense n knowledge. we hv emotions n thoughts.while other creatures do not hv all these things.
so u mean that we shud make their life sad and worse??
no they are all happy but they dont feel they are happy in all conditions
and....they do not have emotions...?
i think so a little bit but not equal with humans