Animals don't know exactly what will happen when they die any more than we do. In the absence of specific knowledge, they simply trust. They trust death the way they trust life: as participation in the Source. What will happen when they die must be okay because what is happening now is okay.
Watch any plant or animal and let it teach you acceptance of what is, surrender to the Now.
Let it teach you Being.
Let it teach you integrity - which means to be one, to be yourself, to be real.
Let it teach you how to live and how to die, and how not to make living and dying into a problem.