The main question is where have the spiders gone, and how far away from there is it physically possible to be?
Go outside at night, and take your smartphone with you. Turn the flashlight on, and shine it away from your face while holding the LED right above and between your eyes. Look at the lawn.
If your lawn is like mine, you will see 4-5 shiny reflections from the grass in every square meter of your land. They're not dew drops. They're ground spiders.
https://en.wikipedia.org/wiki/Ballooning_(spider)
Key quote: "Even atmospheric samples collected from balloons at five kilometres altitude and ships mid-ocean have reported spider landings."