It was not until after the flood, and most likely; after the animals had begun to procreate, that there were any carnivores on the Earth.
Genesis 9:2 and 3 NKJV And the fear of you and the dread of you shall be on every beast of the earth, on every bird of the air, on all that move on the earth, and on all the fish of the sea. They are given into your hand. 3 Every moving thing that lives shall be food for you. I have given you all things, even as the green herbs.
Before that time all creatures including man were Herbivorous.
Genesis 1:29 And God said, "See, I have given you every herb that yields seed which is on the face of all the earth, and every tree whose fruit yields seed; to you it shall be for food. 30 Also, to every beast of the earth, to every bird of the air, and to everything that creeps on the earth, in which there is life, I have given every green herb for food"; and it was so.