Posted Feb 05, 2013
The best thing about growing frogs is that you can easily find a lot of free eggs in the spring. Last year, we were hiking past our favourite pond and stopped to enjoy the view, when my kids spotted a cluster of frog eggs stuck to a reed near the dock. My oldest leaned way out (while we all secretly kind of hoped he'd fall in, because it'd be really entertaining) and scooped up the eggs into a water bottle we had with us. We also filled other empty water bottles with additional water from the swamp so that there would be no trauma or accidental toxic damage when we got the eggs home.
The eggs turn to tiny tadpoles very quickly, and they're really a lot of fun to watch. If one suddenly starts swimming, the water immediately becomes a writhing mass of high-speed black swimmers.
When we saw back legs appear, we released all but a couple of them back into the same pond we got them from. The other ones became adults in about 2 more weeks and we enjoyed them for a few days before releasing them as well.
Obviously, tadpoles can not be left alone with a small child or a sneaky feline, but for preschool and up they are a great learning experience, in terms of both amphibians and the importance of ponds for wildlife.
A few pointers: Don't put them in direct sunlight, or a room that's dark all the time. Once they grow back legs, they need to eat, so add some of the water-plants and algae from the same place you got them if possible. Don't overcrowd them; you need about a minumum of 1 litre of water for every 5-10 tadpoles.