try this it has work for me numerous times with my new baby green, start thawing out the rat, while this is happening got the the cage turn all lights off in the cage, close the blinds in the room if needed any light that are in the room close them you want complete darkness,check up on the snake in an hour or so to make sure your anaconda is in her water dish, if your snake is in the water dish get the food item and place it over the lip of the water dish but make sure the food item is hot and the nose of the food item is not in the water has to be above the water like it is trying to drink. when you have placed the food item cover the front of the cage or the glass part of the cage with a towel now you anaconda, thinks its night time, its feels safe, and the food item is not going ot bite back ....... try this if it doesn't work then im out of options cause this is how mine eats.