1-2cm, "piebald" snails with a "ram's horn" type shell. In a small pond we've inherited, may not be native.
No interactions present.
(Which turned out to be goldfish when they woke up today) in the largest pond, together with foreign water lilies, I suspect these are also introduced.
for the proposed identification. I'd wondered about Lymnaea stagnalis, but wasn't sure, especially about the size. Perhaps they're siblings not yet fully grown.
If you're right, at least they're native!
The slender spire relative to the last whorl is characteristic of this species.
To both of you. L stagnalis it is!
Lat/Lng: 52.4418, -0.2838
OS grid ref: TL167840