Perhaps the most important distinction between the fauna and us is our moral agency. The sow that permits the runt of her litter to starve is not a negligent parent, but a human mother doing the same would be branded a monster. The feline that plays with a fallen baby bird before consuming it is not being sadistic; she is acting like a cat! But any human who tortures an animal is rightly seen as pathological.
Source: A Secular Argument for Intrinsic Human Value – Stand to Reason Blog