Sustenance Over Freedom or Vica-Versa?

Because bread taste better than key.

he can take both

because he was probably starving

Like these poor Zombies...

He wanted to eat then escape

well of course as a rational being he/she/it eats first then because the prisoner is gluten sensitive, which means the bread will have a narcotic effect while starving, and therefore the 'hope the key instills' will be meaningless in that state of mind, so is tossed too far from the cage to be a meaningful concern in the future.

The door wus open

Because he can use the bread to trade with the rats in the walls for a armour suit with iron man based abilities fly through the ceiling and destroy the opposition!

If he took the key, he could just get both…

Congrats on our perspective.

My first thought was spongebob

Upvote for you!