As mostly everyone here knows, there are two conflicting creation stories.
The first one (Gen 1:1 - Gen 2:3) was done by the GODS (check your interlinear note for Gen. 1:1).
The second one, starting at Gen. 2:4 was done by Yaweh.
There are some interesting points concerning animals:
On Chapter one, the gods create the flying animals from the water, but Yaweh creates them out of the ground on the second story.
On Chapter one, the gods create the flowering plants before creating the sun needed for photosynthesis, and the animals to pollinate them.
On Chapter two, Yaweh creates first man, then plants and animals. There could be no plants, because according to the bible, there was no rain and no man to work the ground. Since there were no plants, and animals feed from them, it goes that there were no animals.
Yaweh then works the ground himself to make a garden, and proceeds to make animals for Adam to name and look for a mate at the same time. He doesn't like any, so Yaweh quits making animals from the ground and makes a female from living tissue. (I wonder if all the females of the rest of the animals were created from their ribs, or if it's only the human female the only one created from living cells).
The bible further tells us that snakes could talk. Probably walked in a form of locomotion other than on their bellies, and did not eat dust, as they were punished to do since the first sin.
Since the bible tells us that animals ate only vegetation, God must've changed their eating aparatus unless snakes used their venom to paralyze the plants they ate and chewed with their fangs.