This is a specific conversation about Reptile setup — getting the environment right — ask about yours and get one honest answer for your exact situation.
inparticular.ai
Cold spots with a ball python usually mean one of three things — the heat mat is undersized, it's not being regulated by a thermostat, or it's positioned somewhere the snake can't actually reach it properly. Reptile welfare is almost entirely determined by getting the environment right: temperature gradient, UV lighting, humidity, and substrate all need to match the species' natural habitat, and getting this wrong causes chronic stress and illness. To help you properly: how old is your ball python, what size enclosure are you working with, and is your heat mat currently running through a thermostat or straight from the wall?
She's about four years old, fully grown. The enclosure is a 4x2x2 wooden vivarium. The heat mat is running straight from the plug — no thermostat. I've noticed the warm side isn't getting above 28°C and the cool side is only a couple of degrees lower.
inparticular.ai
That's your problem right there — no thermostat. Without one, the heat mat can't regulate itself, and in a wooden enclosure especially, heat dissipates differently than glass, so you often end up with an uncontrolled surface that's either too cool or dangerously hot depending on ambient temperature. A 4x2x2 is also a good-sized space for an adult ball python, which is great, but it means you need consistent, measurable heat delivery. What size is the heat mat you're using, and where exactly is it positioned — underneath the enclosure, on the side, inside?
It's a 20x20cm mat stuck underneath on the warm side. I assumed that was the right way to do it.
inparticular.ai
Underneath is fine for a wooden viv, but 20x20cm is quite small for a 4x2 footprint — that's only covering a fraction of the warm end. More importantly though, without a thermostat you have no control over what temperature that mat surface actually reaches. Ball pythons need a warm side surface temp of around 30–32°C and a cool side of 24–26°C. Right now you're flying blind. The single most impactful change you can make is adding a quality mat stat. I'd recommend the Habistat Mat Stat — it's a pulse proportional thermostat designed specifically for heat mats, widely trusted by reptile keepers, and it'll regulate your mat accurately within a degree or so. Set it to 32°C probe-side and you'll immediately get reliable, safe temperatures. Once that's in place, you can reassess whether the mat size needs upgrading too.
Where should I put the thermostat probe — on the mat itself or somewhere else?
inparticular.ai
Place the probe on the surface of the substrate directly above the heat mat — not on the mat itself and not tucked away at the edge. You want it reading the temperature your snake will actually experience when she's sitting on her warm hide. Fix it flat against the substrate surface with a little tape if needed so it doesn't move. Once you've set that up, use a separate digital thermometer — ideally an infrared temp gun — to spot-check the surface temp and the cool side independently. The thermostat probe is your controller; the temp gun is your verification.
That makes a lot of sense. Should I also get a bigger heat mat while I'm at it?
inparticular.ai
Probably yes, eventually — for a 4x2 vivarium you'd ideally want a mat covering roughly a third of the floor on the warm side, so something in the 40x20cm or 28x28cm range would serve you better. But don't rush to buy everything at once. Get the Habistat Mat Stat in first, get your temperatures stable, and then reassess over a week or two. You may find the current mat performs much better once it's properly regulated. If the warm side still isn't hitting 30–32°C consistently after that, then upgrading the mat size is the next logical step.
