Thank you! I actually keep a similar bag of mice in my own freezer at home...right next to the frozen waffles! xD

I do understand with the live mice; I don't particularly enjoy seeing them killed, but it is fascinating to watch a snake hunt and catch its prey. I think for most facilities it comes down to how many snakes they have and how much time they have to feed them. If you have time to watch and make sure the snake isn't injured, I think feeding live is a good enrichment that stimulates the snake through hunting behaviors. We have a lot of snakes and we just don't have the kind of time for that level of supervision. Much easier to give a snake its food and walk away knowing there's no risk...we can just check back later to see if it ate. Honestly, the risk of a mouse injuring a snake is quite low, but I've seen a couple instances of those bites becoming badly infected, so I never liked to risk it!