Animal 1 Bees 1 Behavior, Animal 1 Carbon Dioxide 1 Crop load 1 Flight, Animal 1 Foraging 1 Honeybee 1 Metabolic rate 1 Motivation 1 Motor Activity 1 Reward Support, Non-U.S. Gov't 1 animal 1 animal behavior 1 article 1 bee 1 carbon dioxide 1 flying 1 metabolism 1 motivation 1 motor activity 1 reward 1