Long time ago, there was a dying planet.  The planet was very similar to our planet but the inhabitants were very wasteful with the resources until it was too late to save it.  Some of the scientist on the planet got together and built a space craft.  Unfortunately, they had only enough resources to build one that could house only 500 people. 

They gathered their top scientist including biologist, scientist and selected only the best among them.   

Their journey took them many centuries and in the end, they found our planet.  When they landed on Earth, it was still the time of the dinosaurs.   By the time, they reached Earth, many generations have passed but they still remember what happened to their home world and vowed never to repeat the same mistake.  They evolved and adapted to our planet and became insects and lived on Earth since.   They are the first being to start recycling making sure nothing goes to waste. 

I then asked her what the dinosaurs dispose from their body is.  Initial she said, “Egg” but after I repeated the question, she replied, “Shit”.

These insect, will consume shit, leaves and wood that fall from the trees.  They evolved into the different kinds of insects today.  One such insect is the termite.  Basically the termites eat dead wood.  Unfortunately, we use these woods to build houses and furniture, that’s why we call them destructive.

So that’s how insect came about on Earth.

Image via Wikipedia