How does the family end up getting told they need to leave the forest the next morning?

When a bear comes over to the camper, eats some of their food, and begins shaking the camper, Manny climbs out onto the camper roof and sets off a flare. The ranger who comes, after seeing the flare, reprimands them for setting off the flare, as it could cause a fire. Due to this dangerous behavior, they are asked to leave in the morning.