system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why a newly created natural pool automatically gets fish after a while?
gpt
Some manmade lakes/ponds are stocked artificially, ie they just straight up dump fish or eggs in. Other isolated bodies of water, like glacial lakes, are stocked with fish by birds, which carry eggs and/or adult fish and then drop them into water (accidentally).