Kibale National Park, Uganda: Nighttime, a tent. I’m sick. I’m throwing up and dizzy and my stomach keeps cramping, I have to get up. The path to the toilet goes through a grassy clearing and then a few hundred meters through the jungle. I turn off the torch. Fireflies flash on and off around my head and the grass on either side of the path is covered in glowing turquoise dew drops. I look closer and see they are thousands of spiders, lighting my way like stars.