**Risk-sensitive optimal foraging model.**
Imagine a shrew that must decide between patch 1 that always yields **8** pellets under the cover and
patch 2 in which **half** the time there are no pellets and half the time there are **16** pellets.
Both patches have the same mean (8), but the **variance** is greater in patch 2. If our forager
takes **variance** into account, it is foraging in a **risk-sensitive** manner.