In order for an animal to gain mass what does it need?

Food

Explanation: Of course, animals need food in order to gain mass. The food is used to transfer into cells, forming tissues, skin, and muscle to the animal.

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the bald eagle got 50 because everything gets 10% of what they consume and since 50 is ten % of 500 hundred that means the   grasshopper had to have consumed a plant with 5,000 calories of energy

option number one would be youre best option