See title.
Animals eat for the purpose of providing nutrients for the replenishment of energy stores, cellular rejuvenation, and so on. If an animal stops eating, metabolic processes no longer have the 'fuel' required to function and the animal eventually dies.
According to creationists there was no death before the Fall. If animals were no longer in danger of starving to death then why would there be a need to eat?
Genesis 1:29 states explicitly that the food for humans was to be vegetation while verse 30 tells us that animals also were to eat green plants for food. This means that both animals and humans were vegetarian from the start. *
Because both humans and animals were originally vegetarian, then death could not have been a part of God’s Creation. Even after the Fall the diet of Adam and Eve was vegetarian (Genesis 3:17–19). It was not until after the Flood that man was permitted to eat animals for food (Genesis 9:3). The Fall in Genesis 3 would best explain the origin of carnivorous animal behavior.
The first recorded death of anything is when God Himself slayed an animal to cover Adam & Eves "nakedness".
Kind of interesting I think for a couple reasons. (1) symbolic prophesy pointing to the sacrifice of our savior to come ..and ... (2) The power over life and death is in Gods hands only.
Gods creations require certain "earthly elements" to give fuel/energy to maintain their existence.
Why? To answer this would only be speculative ... a theory.
* a interesting note on the new earth all will once again be vegetarians.
Isaiah 65:17
17For behold, I will create
new heavens and a new earth.
The former things will not be remembered,
nor will they come to mind.
Isaiah 11:6-7
The wolf will live with the lamb, and the leopard will lie down with the goat; the calf and young lion and fatling will be together, and a little child will lead them.
The cow will graze with the bear, their young will lie down together, and the lion will eat straw like the ox.
Isaiah 65
25The wolf and the lamb will feed together,
and the lion will eat straw like the ox ...
As .. He originally created in the first place ... Eden restored ;o)