The natural world is fascinating and there will be much to find wherever you live. Isla had an injured pet fly in her bedroom for a few days (until it got sadly squashed by a book) but it led us to feed and water it and we learned about the lifespan of flies (when they don't get squashed!) So you don't even have to go digging in a garden...
There is lots about the life cycle of frogs on Twinkl. You could make a little book or poster showing the lifecycle - or indeed that of any animal. If you are a little older check out TEDEd@Home and put frog into the search bar. Lots of interesting videos there including one on 'frogs that barf up their babies' (though unfortunately these frogs have died out).
For something musical you can't beat the Tadpole Blues (it's a good one for annoying your parents) and perhaps the artwork on that might inspire you to do some of your own. Need some help? This video will take you through drawing a Tree Frog step by step.
Cupcakes are also really easy to turn into frogs. If you need some inspiration click here.
Don't forget I'd love to see any work you do.