Starting in the spring, small blobs of jelly appear on the underside of many of the pond plants.
These are the small egg masses of pond snails and a careful examination under a microscope may reveal the tiny snail embryos.
The eggs hatch within a few days and tiny snails with almost transparent shells spread out across the pond. Like their parents, the tiny snails will feed on algae but many of the snails will be eaten by other pond creatures.
Snail shell is made of calcium carbonate and keeps growing as long as the snail grows. The snail keeps adding more calcium carbonate to the edge of the shell (at the shell opening) until the snail reaches adult size.
The shell helps to protect the snail from some predators, but the shell is thin and many of the snails will be eaten. This is just as well or the pond would soon be overrun by snails.