They will be returning to the wilds of Bloomfield soon, and it's all good.
Yesterday two snails emerged from the tank litter, slowly slithering their way towards a flake of fish food. We never had snails before. None.
And if my lambs are thinking, and they are truly open-minded,and if they trust that no one snuck in and put the snails in there, well, we have some evidence for spontaneous generation.
Further complicating this are the fry that hatched months ago. While most died (as expected), we have about 15 left, and they look less and less like their parents. Oh, they have gills and fins and scales and all that, but they're the wrong color and the wrong shape. (I know about color changes in goldfish--my students do not).
If I have done my job right, a few students will soon announce that we have provided evidence that spontaneous generation happens. If I've really done my job right, those same students will come up with several hypotheses as to how this occurred, and set up an experiment to replicate the results.
Heck, they'll be juniors next year, they can even run the experiment when they get back in September. In the meantime, if a few remain suspicious that maybe spontaneous generation still happens, well, at their age with their experience they should be suspicious. I encourage skepticism.
That's how science works.
No, I don't believe in spontaneous generation. I think....
I also don't believe children should accept what I (or any "experts") say at face value.