Which probe are you referring to? The thermoSTAT or the thermoMETER? The stat probe is best taped directly to the underside of the heat pad outside and underneath the tub so it can't be moved or affected by the snake.
The thermometer probe to read temperatures in the enclosure has to stay inside the enclosure. A good method is to place the probe under the substrate under the warm side hide, then have the hide holding down the probe wire. You'll still have to adjust it, of course, when the snake moves it, but at least you'll know (and can confirm with a temp gun) that you are reading lower temps because the snake moved the probe.

I haven't yet, other than hot-gluing the thermometer probe to the bottom of the tub (which would affect cleaning), found a way to truly secure the meter probe inside the enclosure. Of course, tape is a big no-no! If anyone out there has a good way that isn't 'permanent'...let me know.