I've got my UTH's slapped on the side of the cages, not under, cause I'm not comfortable with the thought of a thermostat or rheostat possibly failing. Of my five, Enigma is the only one that actually plasters up against it, so it's the only one that has the Acu-rite probe stuck to it (on the inside of the glass).

This is the funny thing. The Acu-rite shows it at about 90F, but the temp gun registered it 103F. Obviously gonna have to play with checking spot temps some more, but I do think I'll move it up the glass half an inch to an inch.