I don't post here very often, but I do work with rescued wild caught colubrids. Some snakes will be in a cool tank for one day and be presented a cold dead mouse and attack it like they never eatan before. Others can be rather diffcult and take some tricks to fead.
First fresh killed mice work better for some snakes than frozen/thawed mice. Even with frozen mice it is vital that the mouse is well thawed and warmed. I soak mine in a cup of very warm water until the flesh is soft and warm to the touch.
Presenting the mouse correctly can be critical. Some animals I'll place in a bucket with a hide inside. I put a heating pad under it and get them good and charged up. I then dangle the WARM mouse infront of the hide with a pair of forceps. I wash my hands first and try to keep the 'human sent' off of every thing. I let the snakes stay in the bucket for 30 minutes before feeding, to get them relaxed. Some animals I have to dangle the food, tap thier nose, wiggle and play at this for some time. You can tell right before they will feed. They look at the food from several angles, lots of tounge flicking and then strike. It's import for some of the wild caughts that jerk the food once they bite it, to fake that a struggling mouse.
Other animals I leave the mouse infront of the hide in the bucket and come back a hour later and it's gone.
This can be frustrating, but a warm snake, a warm mouse is always important.
I hope this helped.
Ross