Speciesism is a failure to empathize with those outside one's group. In general, speciesists simply disregard the myriad nonhumans whom humans intentionally hurt and kill. Who cares if millions of mice and rats are vivisected? They're 'only rodents'. What does it matter if billions of chickens live in misery until they die in pain and fear? They're 'just chickens'. They aren't human, so they don't count. Victimizers lack empathy for their victims, but absence of empathy doesn't justify victimization, whether the victims are human or nonhuman.