I don’t see the image or the “first comment” you’re referring to, so I can’t identify them directly yet.
But what you’re describing—small organisms appearing in the toilet after rain—is actually a pretty common plumbing/sewer issue. The most likely possibilities are:
- Sewer worms / tubifex worms (detritus worms): thin reddish or brown worms that live in organic sludge in sewer lines. Heavy rain can push them back into toilets.
- Drain fly larvae: tiny worm-like larvae that come from slimy buildup in pipes; rain can disturb breeding areas.
- Midge larvae (bloodworms): similar to tubifex, often found in stagnant, low-oxygen water in sewer systems.
- Sewer backup debris: sometimes rain causes partial backflow, bringing organic matter (including small larvae or worms) into fixtures.
A key clue is that it happens after heavy rain, which often points to:
- sewer line overflow or pressure changes
- stormwater entering a shared/septic system
- clogged or partially blocked drainage allowing backflow
If you can, upload the image or describe them (color, size, movement, clustered vs single). That would narrow it down a lot.
Also worth noting: if this is happening repeatedly, it may indicate a drain or sewer venting/backflow issue, not just a one-off biological curiosity.