I had a 40g at the beginning of the summer. Little did I know then that her cruising every night was a sign of stress. I thought she was exploring. And I don't mean coming out for a couple minutes, then returning to the hides. I mean all night cruising. Then she started doing it during the day. And then she stopped eating for over a month. I dumped a ton of money trying to heat the thing and insulate it. So I downgraded to a 20L. She stayed in her hides, but I sstill had to struggle to heat the thing.

Then I switched to a tub.

Easy to heat, clean, lift. She eats now, cruises for a couple minutes at night. Seems like a perfectly satisfied bp.

Relating a 40g tank to the wild is comparing apples to oranges. Our bp's are not wild snakes. They are captive bred. Plus, even if they were wild, bp's spend all their time wedged in termite mounds. They don't explore their big world besides looking for food, and they don't enjoy stretching over all the extra space. By getting a huge tank, you are only satisfying a human thought that snakes need a lot of space to be "happy."

But, despite all that, if you really need to have a 40g just to look at it, I give you my blessing. Just be ready to fund it, and deal with the frustration when the bp refuses food. Big tanks come with big responsibilities.