system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does fresh water pond life travel from one body of water to another?

I have a bucket with water in my garden growing pond weed for my fish tank. There are no ponds in any of the gardens on my street, and the nearest body of water is a river, 400m away through multiple streets, yet there are now molluscs and aquatic insects swimming around the bucket that weren't there to start. How did these creatures get there?
gpt
That‘s what a love on fresh water organisms, suddenly its there. There are various ways how they could have gotten in your bucket.
First we have water living insects that are capable of flying, they sometimes choose to abandon they‘re original habitat and look for a new one (most bugs living in fresh water for example).
Then you of course have insects that lay eggs in any fresh water that looks suitable.
Then some animals like molluscs travel by insects or birds. Their eggs or larvae stick to a vector (like a water living bug). Then once a new habitat is reached they drop off and develop normally.