My retic one year before stopped to eats frozen prey. Before he ate. I offer him live and he ate. No as older (a lot and often). I continued offering frozen prey and it denied, but a small live prey he ate . A time the (frozen) prey be hot enought and he ate immediately . He ate only when the rat are enough hot 40-45 degrees of Celsius. The prey in temperature 25-30 degrees C he does not recognize. When the same prey be hot in the 40 – 45 degrees Celcius eats immediately.
Now he does not recognize the live rat and don’t eat. But he eat the same time hot rat (40-45 C). Have you heard something like this again?