Short alkanoic acids stink. Apparently hexanoic acid smells of goats:

Hexanoic acid, as Dylan Stiles (L:tender P:button) memorably mentioned, smells of goats. Goats! Alkanoic acids smell of vinegar, cheese, vomit, poo, and, apparently, goats.
Short alkanoic acids stink. Apparently hexanoic acid smells of goats:

Hexanoic acid, as Dylan Stiles (L:tender P:button) memorably mentioned, smells of goats. Goats! Alkanoic acids smell of vinegar, cheese, vomit, poo, and, apparently, goats.
You left out Formic Acid. :-)
There's also higher weight alkanoic acids, quite a few of which are important.
As for smelling like poo, there's also indole and skatole.
Dave
Buteric Acid is the one that smells like vomit. Distinctly unpleasant. Some was spilled in a stairwell at MIT once. It soaked into the concrete and took 6 months for the smell to go away. Lovely.