This is a very good video done by Zach who started a channel that he uses to inform us of things in our environment like poisonous spiders. He goes over each North American spider that poses a potential risk. He shows where to look for them and what the possible effects of the bite may cause.
I believe it's worth the time to watch so you know what to look out for.
Many of my own classes were held in a very nice park that served as one of my outdoor studios. I took families on field trips that included many kinds of animals. I stopped using my location when I noticed that baby black widows had hatched out. There was a large population of them that year. Although nobody would probably get bit, I never placed anyone at risk, so we changed to other studios for the productions.