Tadpoles in a container out the back

The_B_Man · 05-06-2019 05:46PM #1

I have a plastic storage container that has been left out the back for ages. In the last week I've noticed tiny little tadpoles swimming about. I'd say there's a few hundred!!

I live in a housing estate and the nearest park (nearest water) is about a mile. My back garden is also surrounded by walls. I'm trying to figure out how these things got in there! The only things I put in the container was the roots of some old plants but I'd be surprised if they came in this way. Although it's providing them with some good food as they seem to be nibbling on it.

I also put a big stone in the container for when they grow legs, as I read on the Internet they need somewhere to sit out of the water.

But I don't think they'll be able to get out, as the container is relatively high. I also don't know how a frog got in. Can anyone shed light on this?
Is it possible they're not tadpoles at all, and some kind of parasite?

EDIT: Link to video:
https://photos.app.goo.gl/EhX38rPZ8kpr68ZC6