Answer: In chapter six, Brian ate poisonous berries, which made him extremely sick.
Explanation: Most berries are safe to eat eat, but many are not. If you are lost and find some food source you are not sure of, check and see what other animals are eating them/it. If still in doubt, bail out. Never eat anything that can make your situation even worse. Many bugs like grasshoppers, crickets, and many grubs, ants mealworms, and termites are safe to eat.