Hello, sorry this is a little late.
I believe the correct answer to your question, "an animals long period of inactivity during winter is called what" would be Hibernation.
Hibernation is when some animals (examples would be bears, and wild rabbits) sleep throughout the entire season of winter, when the temperature is too cold for them. They spend time before hibernation usually stocking up food, and creating a warm place for them to stay.
Hope this helps, and have a great day! :)
Answer:
I want to say it's radiation but I'm not sure
True.
Why by Mimiwhatsup: Any organism can form organic substances from nutritional organic substances from simple inorganic substances such as carbon dioxide.