Predators rarely kill and eat all available prey because:
predator and prey species often occupy the same trophic level in an ecosystem
prey species often lack protective mechanisms to deter being eaten
many predator and prey species have a commensalistic relationship
predator species often will switch its prey as one prey species becomes less abundant

If the primary predator of a prey species is eliminated, the prey species’ population will increase to the point of overpopulating the ecosystem. This overpopulation will result in depletion of the prey species’ food supplies as more individuals compete for the same resources and can ultimately lead to the prey species starving.

Explanation: hope it helps ^w^

thinking it would be physical characteristics

it would be heredity