Insects mimicking Preditors

Often you see pictures of insects or animals that looks like predators. They have big spots that looked like eyes, shape of snake, etc. Do they intentionally  evolved to look like one?

My hypothesis is like this. In the process of evolution, the specie have developed with features that resembles predators. Since other animals are afraid of predators, their chance of survival gets better thus they multiply.

As evolution goes, it developed further and those that by chance enhances the feature get better chance of survival and passed down the gene.

Through many generations, the selective survival of those who evolved towards predatory look makes the animal looked more like the predator and today we see the result of the survived specie.

The evolution theory of "survivor of the fittest" does not means that only the strong survived. It actually means that the specie is able to survive by their strength, ability, features or properties. It is the ability to avoid being eliminated.