Animals reserve energy stored in:

🧠 Explanation:

Animals store energy as glycogen, a complex carbohydrate primarily found in the liver and muscles. Glycogen acts as a quick-release energy reserve, broken down into glucose to fuel physical activities and maintain blood sugar levels. Unlike fat, which stores long-term energy, glycogen provides immediate energy for metabolic needs. In mammals, the liver regulates glycogen storage and breakdown, crucial during fasting or intense activity. This efficient energy storage system ensures animals can respond to energy demands swiftly, supporting survival and physiological balance across various species, from humans to other vertebrates.