Segmented, jointed invertebrates with an exoskeleton. They make up over 90% of all known living animal species. Humans like to eat them, raise them, and kill them. We like to love them and fear them. We think some are tasty, and we think some are the most creepy things we've ever seen in our lives.
What we need to keep in mind, however, is that we need to respect them. When it comes to humans and bugs, one might naturally think that because humans are bigger, they are better and more superior.
This would be a mistake. Bugs are crazy awesome. They are well adapted to almost every environment, and can survive a lot more than humans can. We throw all our waste at them and they simply keep on trucking. If any person on this earth is foolish enough to think that this is the age of man, and that humans are ruling the earth, they merely have to look at the facts. Some studies estimate that there are over 200 million insects for every human. That's not even including crustaceans, which are also in this category. We're outnumbered. Badly.
And we're amazingly lucky that their size is limited by their exoskeleton so that movies like this
will never actually happen. (The weight of the exoskeleton would crush them if they were that large)
Thank God. But please don't think that you shouldn't be afraid of bugs. They're disease carriers, they're poisonous, venomous (yes there's a difference between poisonous and venomous, look it up) and all very well adapted to survive. If you don't believe me, check out this link. It's a hilarious but pretty accurate description of some truly terrifying arthropods.
It's not my intention to freak you out with that article, but I do wish to impress upon readers that arthropods are all extraordinarily impressive creatures, and we would do well to learn more about them before they take over the world.