Just to be explicit — I’m reading your words about “bones” as “human bones.” A medium constrictor, 1 to 2 meters long, is easily strong enough to crush the bones of its prey. A 2-meter boa can crush a rat’s ribcage so fast it sounds like popping bubble-wrap, and the rat dies nearly instantly.

That’s if you live-feed, which is generally considered unsafe. Larger snakes need larger food, and larger food tends to fight back. Yes, in the wild the snake wins almost all the time, but if the snake’s your pet you want it to win 100% of the time. Most responsible snake keepers will thaw frozen food, and most constrictor can be trained to eat dead rodents, as long as they’re warm enough.