Question

What is an animal defense mechanism?

Answer 1

An animal defence mechanism would be something that enables the animal not to be caught by a predator.

Explanation:

This could be a bad taste, such as some frogs taste bad to predators and so they are spat out, this can be the same as smell, some insects create a horrible smell.

Another a defence mechanism could be running away from a predator.

Spikes, to deter predators from attacking them, or to possibly make it harder for the predator to eat them, or make it more effort to eat them.