Caterpillars munch on:
Adults take nectar from a range of flowers including:
This butterfly spends the winter as an adult, hibernating somewhere dark and sheltered such as a shed, barn, log pile, hollow tree or an attic.
There is even more about this species on the main Butterfly Conservation website
A book from 1893 contains a report of three Small Tortoiseshells hibernating in a church bell, apparently undisturbed by the noise and vibrations through the winter!