You don't have to worry as much with ball pythons about them associating you with food...a big monitor or burmese python, I'd worry about, but balls aren't exactly going to think of you, godzilla-sized-human, as a potential prey item. I feed all of my snakes in their cages...I can count on one hand in the past 16 years how many times one of my snakes has bitten me. Every time it was my fault for not washing my hands after handling rodents!
Ball pythons are not dogs, and won't appreciate a 'treat'. They will not be less hungry, because a pinky is next to nothing for a ball python of any size. Even hatchlings need more than a pinky.
Constantly cruising snakes may mean that something is not quite right in your cage. My snakes only do a lot of active inspecting when they're hungry or if the boys are looking for girlfriends. As I type, the only snakes moving around are the two sexually mature males - everyone else has found a nice spot to hide and is hiding. The rest will move, yes, but they do not really cruise the entire cage like they are searching for anything...unless it's coming up on feeding day.
So, it may be that your snakes don't like sharing space, it may be that they are hungry and need to be fed bigger prey items or maybe just a little more often (every 5 days instead of every 7), or maybe they don't like their hide spots. A couple of my snakes absolutely hate fake rock hides, but love cardboard boxes. Go figure.
A truly obese ball python is one that is so fat it can't bend itself in half. When you hold it, it should be able to grip you firmly and crawl around. You want a nice, round little snake. If you can see a backbone sticking up, it's too skinny. If you took a cross section of a healthy snake, it'd be like an oval. A skinny snake will look like a triangle.
It is pretty hard to get your ball python obese. Most ball pythons will stop eating (seemingly for no good reason) when they start to gain a lot of weight.
~jenny
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