Fake ethical problems solved

Yesterday on an ep of TBBT Sheldon brought up the "problem" of the starving donkey and two equidistant bales of hay. Amy tells him that's plagiarized from Aristotle, though the latter posed the problem of a man dying of thirst and hunger with equidistant food and drink. Both problems conclude in death, as the cubjects cannot make up their minds what to do first.

Well, there's no problem.

We know now that lack of water kills a lot faster than lack of nutrition. So someone suffering from dehydration and starvation should drink first and eat afterwards.


Now, the Turtledove donkey conundrum is alive and well: a starving donkey is offered two equidistant bales of hay, but both are poisoned and the donkey knows this. Behind it is a smaller bale of hay that is not poisoned, and it knows this too.

Question: why does it then eat one of the poisoned bales?