Bloods use the detection of heat by their labial pits more than any other sense for prey identification. It will even over-ride what they are seeing visually. That is why it is common for blood pythons to refuse to strike room temperature f/t prey items that are being moved in front of them, and then hit that same prey item immediately after it is warmed. I have also seen bloods strike at water bowls that had just been cleaned and still retained heat from the warm water rinse when it was being placed back in the cage. Not sure if this was the type of behavior that you were seeing, but it is quite possible.

Kelly