Things Only Adults Notice In Ice Age

The problem with telling stories about animals that behave like humans is that at some point the mixing up of animal rules and human rules lead to some uncomfortable speculations. Take for instance the friendship between Diego, a predatory tiger, and Manny and Sid, two animals that the tiger would ordinarily feast on. 

A big part of "Ice Age" is Diego learning to stop seeing Manny and Sid as prey, and start seeing them as his friends instead. In the end, Diego decides to become friends with the other two rather than trying to eat them. But you have to remember that Diego is still a carnivorous predator, which means sooner or later he is going to eat a fellow animal to survive. 

And now we know that Diego's next prey will also be a talking, feeling animal just like Sid and Manny. Later movies even show the animals of that world, carnivores and herbivores alike living together in a close-knit society. That means every time a predator eats a fellow animal in this world, they are eating someone they knew, spoke to, and were maybe even friendly with. In human terms, that's called a cannibalistic society.