One of the major sources of entertainment and interest for my sister and me when we were children was the flora and fauna of the garden. Our garden didn't have anything particularly out of the ordinary in it, but we were quite easily entertained, and not very fussy, which are useful qualities for a village upbringing.
When I was eight I used to spend days mashing up different plants in jars of water, to see which made the best colours (results: elderberries for purple, and goosegrass for a good bright green, FYI) and I thought the mosquito larvae that turned up in some of my unused jars of water were bloody amazing. The way they breathed air through a tube sticking out of their arse, hanging upside down on the surface to do it until startled, and then swimming off by flicking their whole bodies one way and then the other was like no other animal I had ever seen.
I kept a small menagerie of them at the bottom of the garden, made sure their water was topped up and clean, and sometimes sorted them by size and life-cycle stage into different jars. Before they became adults and flew off (probably to come and bite me in the night), they went through a pupal stage in which they were comma-shaped and had two little horns instead of arse-tubes to breathe through and this was all really really interesting because I got to observe it happening, wondered what the hell was going on and eventually found a book that explained it. Properly retro, or as we didn't call it in those days, The Only Way You Could Actively Find Things Out Without Just Asking An Adult Who Might Not Even Know Anyway But Possibly Wouldn't Admit it and Could Very Well Just Make Something Up.
So far, so kind-of-a-bit-gross. I would like to clarify at this point: I grew out of this. A long time ago. I no longer deliberately cultivate larvae of any kind*. (I did take A-level biology, later, though. We studied really thin slices of beetroot under microscopes for an entire term, and this may have got something out of my system, although I'm not sure what.)
Some years later my sister developed an interest in snails. I have to say she had rather better taste in garden wildlife than me, at the very least because snails don't ultimately turn into winged disease-carrying biting things. As far as we observed, anyway. For a month or so one summer, there was an old fish tank in the garden into which she'd collected loads of snails. We provided them with water, fresh food every day, shelter, whatever else it said in the books about snails that you should include when observing them, the works.
They were eventually all released back to the wild, but while they were with us we got to see something which was not in any of the books. And - not that I've asked everyone I've ever met, because it doesn't come up in conversation that often - nobody else seems to have heard of it happening. I also can't find any reference to it on the internet anywhere. But it wasn't a dream because I have a co-witness, and it happened.
One of the snails my sister found had a small hole in its shell - about 4mm across. We were concerned about this snail, and wondered if we could help it. Books said that snail shells were formed with the aid of calcium, which came from limestone that occurred in the soil. They didn't explain the mechanism by which the snail shells were created from the limestone, so we weren't sure if getting some limestone and putting it near a snail would actually work in this case. But we thought it might be worth a go.
If you went out of our front door, crossed the road and went a little way up the track that went out round the field, on a clear day you could see the Uffington White Horse marked out in chalk on the hill in the distance. Some weekends my family would go up there for a walk. It was the best place for a walk - as well as the hill where the horse itself was, there were tracks around woodlands and across hillsides along the Ridgeway, and even when it was raining it was still brilliant because it had really interesting mud. It was beige, for a start. Beige can no longer be called boring when it's mud that's doing the being-beige**. The texture was like clay: the puddles were like the slip we mixed up for sticking bits of clay pots together in art lessons, and the thick mud at the edges almost like the clay we used. But beige.
The light beige colour, of course, came from all the naturally occurring limestone mixed in with the clay soil -- limestone-filled trenches being what the horse was constructed from on the hillside. Sometimes you could find whole lumps of it lying at edge of the woodland track. And so the weekend after we found the holey snail, we made it our mission to find a good chunk of the stuff, bring it home to the snail, and see if anything happened.
A lump of limestone was duly captured, and when we got back we located the injured snail in the tank, and put it directly onto the limestone. It was inside its shell, but after a minute or so it emerged. And then it started work: we saw a bit of radula action going on as it examined what it was now situated on, and then as we watched we saw it bring its head inside its shell, put its mouth on the edge of the hole, and spit out what was presumably a mix of snail slime and chewed up limestone. Then it stuck its head back out, did some more chomping, then went back in and spat out some more on the edge of the hole. And within an hour, they was a thin membrane covering the entirety of the hole in the snail's shell. It knew exactly what to do, immediately. It was all a lot more straightforward than we were expecting.
It was one of those things that you find out when you're young, and are just like, "Huh, ok, that's how that thing works", and accept it and carry on learning more new stuff -- except that after that I never heard of it or saw it ever again, and realised about 15 years later how cool and weird it was to have seen something like that.
It is possible that that particular snail was just amazingly intelligent and innovative. But I'm not about to go around puncturing any snails in order to replicate the process, because a) it's mean, b) I have more pressing matters to attend to and c) I don't live near a source of limestone anymore. But presumably a normal stick of chalk would also work. So. Just in case anyone reading this needs to know what to do next time they come across a holey snail: let it eat chalk. And this time, given that it's not 1996, if it Does The Thing, make a video of it so we have proof, because there's none of this on YouTube and there's kind of still the possibility that it was a collective hallucination after spending too long hanging around Wayland's Smithy.
* Not even human larvae
** Well, I mean, it can, but I'll just argue that you have no taste in mud and can't appreciate a decent interesting example when you see it