Insects are the most diverse group of animals that ever lived.
There are more species of beetles than any other type of creature.
Many years ago, some ground wasps decided they liked living in burrows so much that they never left them. They became the first ants.
During the Cretaceous period, oxygen levels were higher than they are today. Insects have no lungs, which limits the efficiency of gas exchange. These higher oxygen levels allowed insects to grow to much larger sizes than today.
A 10 foot long, 18 inch wide millipede fossil has been discovered. It is probably the largest land arthropod that ever lived, and entirely too large for my taste.
Coconut crabs, a type of hermit crab, inhabit the south pacific and Indian ocean. They are currently the largest arthropods that live on land.
Trilobites were the first arthropods. While they weren't insects, they served as a 'prototype' for the basic design.
Insects have been found living in just about every place of earth, including Death Valley and Mt Everest.
An exoskeleton is a fantastic design if a creature is small, but they have an inherent maximum size. If they get too large, they are unable to support the weight of the creature inside.
An exoskeleton allows more room inside limbs for muscles. This is one reason insects are so strong for their weight.
Some dung beetles have been observed pushing 800 times their own weight around. This is equivalent to a human being moving 80 tons, or about two tractor trailers.
Insects are a vital part of just about every terrestrial ecosystem.
In general, insects dominate the land and crustaceans rule the seas. While there are marine insects and terrestrial crustaceans, these are relatively rare.
There are probably millions more species of insects out there, although this depends somewhat on the definition of a species.
By weight, there are more ants than there are people. Luckily for us, the ants don't seem to have learned this yet.