hatsu, you need to buy a second terrarium and a second heating device for it. Housing 2 ball pythons together is not recommended unless they are breeding. Your under tank heater needs to be regulated by a thermostat. If you don't have one your pad can fail and heat up to over 130 degrees and injure or kill your animal. Also 75 degrees is a little too cool. Your cool side shouldn't dip below 78. Hot side in the low 90s. With some ingenuity your 20 gallon long terrarium can be divided into two cages with the heat sources in the middle. One of your snakes is not eating probably because of the stress of keeping them together. Just because they do it at the store doesn't make it a good idea. There are all kinds of risks to the animals' health that are not worth it. Please read some care guides on ball pythons.
http://ball-pythons.net/forums/showt...s%29-Caresheet
Here is my 20 gallon long divided into two terrariums with a thermostat regulated UTH providing heat to both.
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