MY (SON'S) HORSEFIELD TORTOISE HAS COMPLETELY BURIED HIMSELF IN HIS VIVARIUM, HASN'T MOVED FOR 3 DAYS. IS THIS NORMAL BEHAVIOUR ?  IT IS THE FIRST "WINTER" FOR HIM / US SO NOT SURE IF HE IS GETTING INTO HIS WINTER SLEEP. WAS EATING+ DRINKING NORMALLY BEFOREHAND.  ANY ADVICE MOST WELCOME, THANK YOU

Hiya,

I would be inclined get him out of the vivarium for starters so you can offer a range of temperatures. It could be it's too hot, or too cold?

Here are care sheets you might find useful:-
http://www.tortoise-protection-group.org.uk/site/87.asp

HTH