Predators, suffering of animals

Reply to a Facebook-post:
:(
Both the cat and the bird are sentient beings. Both love life, both love their family. Both feel suffering, joy and love at times. The individual's family suffers when their beloved family member is killed.
So it so sad that many sentient individuals of species throughout the ages decided to kill and eat each other.
I think it is so sad when a fox kill or a rabbit, or a snake kills a human, or a human kills a cow.
Please watch this video: http://www.youtube.com/watch?v=uQCe4qEexjc