[I guess I need an answer fast] How to humanely kill a rat

While it may raise the reflex to breath the act of breathing replaces oxygen with pure carbon dioxide. The rat should have passed out quickly which is what was observed.

No. For one thing, you bait the zapper with peanut butter or chocolate - things obligate carnivores have zero interest in. Also, cats and small dogs simply can’t (or aren’t interested in) squeezing themselves into very very small spaces for a meager reward. Even for the rat-sized one the opening was like an inch square.

I had three cats and one ratter-terrier-killer-small-dog and none seemed either interested in, nor in danger from, the rodent zapper.

First offer it dinner and trinkets. Transmit germs while doing this so you can wipe out it’s family after dinner. Get it to recruit it’s annoying neighbor rats for forced experimentation after capture. Then put it in a hoodie and shoot it. Engage in a lot of hand wringing about how unjust it’s life was and that you would like to export your “humanity” program to rats all over the world. That’s how we do it in America. We’re humane humans.

When I worked in a lab, we killed rats by holding the head in one hand, the tail in the other and giving a good sharp pull. This snapped the spinal column instantly and they died. This didn’t work with guinea pigs and we dispatched them by hitting their heads hard against the edge of a sink.

Freezer is my chosen method for dying aquarium fish also.

How reliably did those two methods work?

I realize that the OP’s problem is solved - and quite thoughtfully, Well Done ACM!

But I’l say this for future surfers who may need the suggestion: If you are going to go with crushing, please put the creature in a bag or soft container and place it in front of a car tire, then roll over it back and forth a couple of times.

This is much quicker and surer for the creature, and saves you having to live with the repeating flesh memory of the crunching of bones. Even though I had heavy combat boots on, I can still feel it in the instep of my left foot any time a subject like this comes up.

Yeah a shovel to the head will do it. Slowly freezing to death sounds horrible…

Well, where I was raised in Idaho we’d a just hit it in the head with something heavy like a hammer or a shovel or axe handle. Or stomped it. Of course it’s sort of a hypothetical since in Idaho the dogs would have killed it post haste.
I was visiting an uncle one time up in Mud Lake, an old sheepherder, who shot the varmints in the house with a pistol he kept handy.

Decapitation or massive blunt trauma to the head might be marginally faster if done correctly and successfully. A slight miscalculation in aim or force can lead to a very unpleasant experience for the rat and a terrible memory for the human. And the OP stipulated that wasn’t the way he wanted to go.

Contrary to some internet blogs decrying the practice, freezing (preferably a deep freeze) is humane in context when you’re talking about an already severely injured animal who is in shock and dying. It would be more traumatic for a healthy animal, but still less so than a misplaced shovel strike that doesn’t kill it.

Unless the animals injuries are fatal, and depending on how cold your home freezer is, you could be condemning it to just serious pain though couldn’t you? It could take hours for it to eventually lose consciousness.

I have no proof either way but I certainly can’t see how putting a live animal inside a freezer is a more humane alternative to a quick kill. Even if you stuff up the first attempt with a shovel/hammer etc and just cause pain, a quick second or if needed 3rd shot means it’s all over in seconds, not hours.

Given the choice of decapitation or freezing decapitation is the overall more humane choice, with the big disclaimer that it is done accurately and effectively without undue handling or stress to the animal prior. But I think you are downplaying the suffering and stress that would be inflicted on the animal and person in the very common event that the first blow didn’t kill instantly.

Either way, that wasn’t an option for the OP and given their circumstances - someone who was presumably at home at 5AM with a shocky rat twitching on the ground - the freezer is still IMHO an acceptable alternative to watching him writhe in pain or trying to stomp him to death or throwing a phone book at him.

Hypothermia is an anesthetic before it becomes a cause of death. Have you ever been advised to put ice on a painful injury? Same applies to the rat’s injuries. At 28-32 F. an average sized rat would be completely numb within minutes and unconscious soon after. Given his state of shock and the endorphin flow from injuries as he prepared to die, he would not experience the same sense of being trapped or panic like a healthy animal would during those few minutes. It would be a cool, dark, quiet comfort to die peacefully with a little pain relief thrown in.

Freezing as a method of euthanasia is not recommend by any ethics committee or scientific institution, where it can be assumed an instant death can be caused reliably and expertly using other methods. However when it comes to a dark porch at 5 AM and a severely injured rat such assumptions are not so clear.