It's not hard to tell insects apart from other tiny animals such as ticks, spiders, scorpions, centipedes, millipedes, and isopods. Many adult insects also have wings. Insects are very important in our world and this fact often gets overlooked. There are more insects than all other animals combined.
Insects are also extremely abundant in terms of their population levels.
Some insect species have inhabited the planet for at least 350 million years. We know this because of the fossil records that some insects have left behind. Some insects have changed very little since the dawn of time, others have changed greatly, and some have become extinct. They can even be found inside plants and other animals. Each insect is adapted to a specific habitat.