First, a warning. This is a hard one to write so please don't follow up with rationalizations about how it's not our fault. We know reasons why it wouldn't be, but we can't prove that, and being told it isn't doesn't help just now. Empathy, sharing the sadness, that helps.
We caught one of the mice who's been prowling around the house after weeks of effort, more on that story to come, on Thanksgiving morning, naturally, because that's the toughest time to get stuff needed for a trapped mouse. We put her in a translucent plastic bin that wasn't a very good holder but would do for the day or two we needed to get a proper cage ready. She spent the day popcorning, leaping up and thumping the bin top, with this steady dribbling thump ... thump ... thump ... thump ... thump … thump … thump … thump … thump that was the kind of funny which makes you feel horrible for giggling at.
The day after I drove around town looking for hardware cloth, wire mesh, so we could fit the outside of a cage for house mice; wild mice are smaller enough they'd fit through the bars, especially if they tried, which this mouse was trying. Tractor Supply Company had none. Michael's (a long shot, but they were just next door) knew what I was talking about but had none. Lowe's had it, but not in the quarter-inch mesh we needed. Home Depot finally had rolls. I think it was there that I lost one of the gloves bunny_hugger's mother knitted for me for last Christmas.
We spent time measuring and cutting and tying with galvanized wire the mesh to the cage and had to think how to transfer the mouse, since there was no chance we could pick her up. We got a big cardboard box, and put the new cage in, and the old bin, and figured we could try to grab her but if she didn't go for it she'd at least leap out of the bin and would eventually have to wander into the cage if only by accident. We weren't sure just where she was because the bin was translucent. We lifted the lid and I saw where she'd run, into a cardboard tube, and I tried telling bunny_hugger where the mouse was and finally decided to just grab the tube and drop it in the cage and slam the cage lid tight, which we giggled about because somehow that all worked.
The mouse climbed all around the cage looking for the way out, but pretty soon got used to the idea of being in the cage and started setting up a nest in this little plastic pod on the top. She built a great little nest, using all the tissue paper we gave and making neat little chambers and even reaching through the bars to grab strands of hay that had fallen from when we fed our rabbit. We were impressed with her industry and the way she would monkey-climb sideways the length of the cage to get somewhere; you don't think of mice as great climbers but she showed her power.
Twelve days after we first trapped her, we found her dead.
She was laying there, in the bedding, looking like a perfect little adult mouse, only dead.
There's no really satisfactory explanation that we have. Could it be old age? Conceivably, but her hair wasn't grey, her eyes had no cataracts, she didn't move arthritically, she had none of the tumors an old mouse gets. And a wild mouse, saved from predators and harsh elements, can live three or four years; while it's possible we caught her in the last two weeks of her two hundred weeks of life, the odds are against it. Starvation? We were feeding her dog food pellets, three or four a day, and we could count the remainder. She'd eaten all but two days of food. Dehydration? This is the hardest explanation to rule out, but she had a water bottle, and it wasn't full any longer, and a mouse is very good at finding sources of water. Yet there wasn't much water missing ... but mice don't need very much water. But who ever heard of a mouse that couldn't figure how to work a water bottle? Wouldn't she have seen the water left over from bunny_hugger's tapping to test that the bottle worked?
Disease? But she was active and alert and busy, right up to the two days before she died. A little cut she'd gotten when first trapped had healed over. We can't rule it out, but if she was diseased, then we don't have the evidence to show it. Stress? She was obviously scared when caught or she'd not have popcorned so, but, she was clearly not too afraid of humans or she'd not have run out in the middle of the floor when we were trying to catch her, and she showed no sign of distress after she got into the proper cage and started work on nest-building and setting up a separate bathroom chamber and otherwise keeping house.
So we have no really satisfactory explanation, although the dehydration one keeps haunting us. It seems the least strain to suppose she somehow didn't know how to work the water bottle. If we had imagined it we could have set out a little dish with open water or given her apples or wet bread or something. To die of being ever more thirsty is horrifying. It's inspired evil thoughts in me, anger at the mouse for not working out how to use the bottle, even though there's no reason to suppose a wild mouse should just imagine how such a bottle works and the mouse certainly didn't ask to be forced into that. That's my guilt talking, and the extra guilt for feeling angry at the most blameless part of this sorry business.
I know that we took responsibility for caring for this mouse --- we planned to shelter her till spring and then set her out where she could live not in our home --- and not two weeks later the mouse was dead. And we don't know why but we can't be convinced that if we had acted more wisely the mouse would not have died.
bunny_hugger took the cage apart the next day, hoping to at least force some of the misery out, but the feeling is raw yet.
Again, I appreciate all your sympathy, but please do not assure us that mice just die like that.
Trivia: According to the Dutch chronicler Nicholaes van Wassenaer, by 1624 there were no more than a dozen of the much-praised Semper Augustus tulip cultivar in the Netherlands, all owned by a single man in Amsterdam, a person van Wassenaer is careful to not name. Source: Tulipomania: The Story of the World's Most Coveted Flower and the Extraordinary Passions it Aroused, Mike Dash.
Currently Reading: From Eudoxus to Einstein: A History Of Mathematical Astronomy, C M Linton.