The hibernation of animals is a purely protective action against adverse conditions  Scientists proved through experiments: the main causes of hibernation animals,first, the decrease in environmental temperature, second, lack of food  Animals hibernate will reduce thyroxine and function of adrenal glands at the same time, The gonads are normal development, the animals after hibernation anti-bacterial disease ability increased than usual, hibernation is obviously beneficial to them, they wake up the following spring with a heightened sense of movement, appetite, and renew  youth in every organ of the body
Many insects hibernate not as Adults or Larvae but as Pupae or Eggs.
 Thus, during hibernation, the muscles of the nervous system remain fully active, while metabolism is kept to a minimum