About a month ago, dd took this photo of our pond frogspawn.
Now the tadpoles have 'hatched' and we've decided to make use of our enormous fish tank to observe the changes in the tadpoles over the coming weeks.
Previous attempts, many years ago, to keep tadpoles in small tanks were unsuccessful. I suspect the main problems were keeping a uniform environment and preventing build-up of wastes. However, there was also the problems associated with having other carnivores in the tank - for example great water diving beetles. If you get one of these in a small tank, they'll eat everything (including tadpoles). We know he was the culprit because one morning he was still chewing on a bit of tail!
There is some useful info on rearing tadpoles on the CLEAPSS website here and there are some suggestions for experiments/ investigations that the kids can do. I'm not sure I should tell my bunch about the 'how fast does a tadpole swim' experiment as it might bring out their competitive side and lead to weeks of tadpole-in-a-tube races.