i have the UTH for mine AND a light, i put the light on during the day because my house is extremely cold [[68-72˚]] so i need it to keep the air temp. up, but at night i put the UTH a little higher and put paper over the glass to make sure it doesn't get too high and that seems to do the trick, she does seem to know me, cause she'll let me hold her and play arpund with her, but if anyone else tries to hold her she'll curl up into a ball until she's either back on the cage or into my arms, it ujst might be my wishful thinking though =P