I've always found spiders to be fascinating with their eight legs and venom injecting fangs.
I am scared of spiders but I know they eat a lot of insects. They are good to have around.
I definitely appreciate them eating all the bugs. There are found worldwide except for Antartica, air or sea.
Yeah, I could see Antarctica being too cold for them. I am fascinated at how they can build webs. What an amazing feat.
Another surprising thing is that they are the order with the seventh most species in it compared to other organisms. 
I know there are lots of different kinds of spiders. Some tiny ones and some huge ones.
There are at least 45,700 spider species and 113 families of species. Its crazy how diverse they are and how they have adapted so many different traits for survival. 
That is absolutely insane. I had no idea there were so many species.
Another cool thing is that unlike most arthropods spiders do not have exterior muscles and actually move their bodies using hydraulic pressure.  
Whoa, that is spectacular. I didn't think insects had hydraulic systems for movement!