Hi,
You dont want the probe from the thermostat inside the tank at all.
Having it in there just makes it possible for the snake to affect it by P'ing on it or moving it which could throw the readings off so much it can lead to overheating the enclosure.
The most recommended place for the thermostat probe is between the UTH and the bottom of the tank on the outside.
The thermometer probe however can be placed on the glass inside the tank under the warm end hide to double check that, even if the snake burrows, it is not exposed to dangerous temperatures.
You then adjust the depth/ type of substrate above that until the temps inside the hide are correct.
**edit**
Dang I type slow.
**end edit**
dr del