Yes, feeding live could be the problem as it can be intimidating and is less safe. It would be a good idea to switch to frozen-thawed or at least pre-killed prey for them. Also, you need a temp gradient from about 80 on one side to about 90 on the other for the snakes to thermoregulate. If they don't have a hide around 90, it will be difficult to digest because their metabolisms rely on external heat.

Take a couple days and make sure the temps are right with a digital thermometer. You can get a great one that will read both sides of the tank and the humidity as well for about $15 at WalMart with their outdoor thermometers. If the temps aren't right, you can buy a human heating pad at WalMart for about $10 without auto-shutoff and put it under the side you want to be the warm side on its low setting. Once you get the temps right, let the snakes rest in them for a few days (in heavier, snug hides if you can, then try feeding again and you may well have a feeding snake.

If you have any questions, please do come here and ask because this is a great community of both experienced and new snake keepers who are happy to help your snake get a good setup.