A bit of variation is fine.. but I wouldn't go more than 5 degrees from daytime to nighttime.
It is not needed. These guys spend all their daytime in the wild in burrows, where the temperature is a bit more stable than the daytime highs, and come out at night to feed and bask on warmed ground.
Last edited by mainbutter; 09-15-2010 at 07:57 PM.