my corn snake has been hiding for about 6 days why?

  my corn snake has bin hiding for about 6 days and i cheked on her 2day and her eyes look normal so what can it be
If your in america, particularly the northeast, fall is upon us. Corn snakes hibernate (or brumate rather ) during the colder months. My advice: just make sure the terrarium is warm, and that its well fed. Another problem might be that your terrarium is just too cold. Being cold blooded, snakes depend on external heat sources for their internal processes. For instance, snakes need sufficient heat in order to preform metabolism. If it's too cold in your terrarium, your corn snake will become sluggish because it can no longer digest its food or process energy. When did you last feed it? Its not uncommon ( for ball pythons and other large snakes) to hide away and become inactive for the next few days following its last feeding. Try to keep your terrarium around at least 70 degrees Fahrenheit or more, and see if that doesn't help. If not, give it a few more days then call a vet. Hope this helps, good luck.
Snakes by nature are reclusive, corn snakes are friendly but they still burrow under their bedding or go into their hide. Unless this is abnormal for your particular snake I don't think you have anything to worry about.