God created a world in which one creature consumes another to survive. We may wish it was otherwise; we may think it would have been a better world if God had made it so that we humans could synthesize energy from the sun, but that is not the world God created. Besides which, even grass which does photosynthesize its energy relies upon nutrients in soil. Many such nutrients are provided by the decay of dead creatures. Whether or not one sees life as created by God, we must admit that our planet can be a harsh and competitive place. For Christians, such observations must be part of how we understand ultimate questions about the manner in which God created life and death in the Garden of Eden. Our theology has not yet fully wrestled with some of the implications of the lion and lamb created prior to humans.
Recently it has been discovered that some species of Praying Mantis can kill and eat hummingbirds.