The actions have nothing to do with anything “natural”.
In “nature” the puppy’s mother or father would not have “fed” the puppy to the snapping turtle; they would have defended it against the snapping turtle.
It was a captive situation all around, not a natural setting and not what would have occurred in any natural setting where a puppy and a snapping turtle would have been found.
The teacher was only demonstrating his own cruelty.
He could have used a pineapple.....
“The teacher was only demonstrating his own cruelty.”
Well said.