Generally, Petco and Petsmart make you sign a piece of paper promising that you won't feed pet mice to a snake. I don't think that there's a health issue involved in feeding one of these to your snake. You just have to be willing to sign something falsely. If you're in a position to order frozen rodents online, you could order from Big Cheese Rodent factory on Monday morning, and you'd have frozen feeders by Wednesday afternoon. (I mention Big Cheese because I just made my first ever rodent order and used them. My only concern is that my ball python has never taken a gray rat, and most of these were gray. Other places could get the same feeders to you by Tuesday or Wednesday as well. Big Cheese offered me overnight service.)
If your snake didn't take a f/t rodent last week, you might look harder for a live rat pinkie to feed him. My girl started on live rat pinkies.
Where do you live? If you're willing to drive a bit, there's probably a store where you could get feeders tomorrow. Where did you get the one that you offered last week? Can you get another one there? How much did you heat it and for how long? I like to heat them for at least 20 to 25 minutes in water to ensure that they are warm all the way through.
You might want to go through the feeder ads here on kingsnake.com and look for a place that's near you. Some of them will sell live feeders if you're willing to pick them up at the facility. Others are mail order only, and I doubt you'll find one that will ship live feeders.
I don't know whether I've helped you. I'm sorry if this isn't what you needed.
I wish you luck. I'd have gone crazy if my little girl didn't eat for the first month that I had her.
Bill
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It's not how many snakes you have. It's how happy and healthy you can keep them.