If you buy an enclosure for an adult ball python and going to place a hatchling in it. I would buy a 6 qt tub from walmart (sterilite) for around 1 dollar. put air holes in it. place the tub inside the adult tank a little less than half of the tub on the heat tape. get the select a size paper towels ( half sheets) to place on bottom of tub. get your correct temps by using a temp gun and place your snake in it. when the snake gets to about 250 to 300 grams get a larger tub and do the same. you don't want to make a snake a problem feeder cause of stress. They live in termite mounds in the wild and have very little head room most of the time. your second question, the probe should be placed at the hottest spot. which is above your heat tape and it could be placed inside the enclosure right above your heat tape or heat source. in my racks with belly heat, the probe is placed right on the heat tape. this controls your heat, but you should use a temp gun to get a correct temp in your tub. not the thermostat reading.