Do Boa Constrictors have run-ins with Alligators?

Answer 1

Yes, because of humans. Boas and alligators do not naturally occur in the same geographical locations, alligators being restricted to North America (and China), while boas are found in Central and South America. However boas that have either been released or escaped from pet owners have now formed a breeding population in Florida. This means boa constrictors now do have run-ins with alligators, although a far more notorious constrictor introduced to Florida is the Burmese python.

Answer 2

Earlier this year I saw a program on National Geographic Channel about a huge gator that was eaten by a large constrictor snake (I think it was a python but it could have been a boa, either way it was a snake that had been a pet and then escaped or was let go).
This happened in Florida, but the odd thing was that somehow the snake's belly burst open and the photos of the incident show the gator's tail sticking out. It seems that the snake literally bit off more than it could chew...it killed the gator, swallowed it but was somehow unable to digest it.

I think the show was something like "Snake vs gator" or something to that effect. You could check National Geo's listings, or you might be able to download part of that episode online. I wish I could be more specific, but that's about all I remember off-hand.