After the story aired, NPR was contacted by snake experts who strongly suggest that a snake's reluctance to bite a religious serpent handler may have more to do with the creature's poor health than with supernatural intervention.

The herpetologists at the Kentucky Reptile Zoo have been following the activities of Pentecostal snake handlers for years. They have watched hours of video of snake-handling services and examined snakes used in church.

"The animals that I've seen that have come from religious snake handlers were in bad condition," says Kristen Wiley, curator of the Kentucky Reptile Zoo, a facility in the town of Slade that produces venom and promotes the conservation of snakes. "They did not have water. The cages had been left not cleaned for a pretty long period of time. And the other thing we noticed is there were eight or 10 copperheads in a container that was not very large."

What's more, she says there was no fecal material in the container, which indicated the snakes were not being fed. Riley says a snake that may be dehydrated, underweight and sick from close confinement is less likely to strike than a healthy snake. Moreover, the venom it produces is weaker.