Personally with all my f/t eaters I just toss the rats in and check the next morning. More often than not they've eaten them, but I once made the mistake of becoming complacent and assumed that they were all eaten. I didn't get around to going down to check the morning after feeding, and the next day holy lord did it smell BAD!
TL;DR: yes, leave it overnight, but make sure you check the next morning!
omgitsnikita: It's NEVER but NEVER a good idea to leave a live rodent unattended with a snake. They can do untold damage and even kill the snake if the snake is not interested in eating. That may not have been what you meant in your post, but I just wanted to clarify in case.
Reply With Quote