"You see, the smell of that many chickens in one place was enough to attract weasels. A lot of weasels." - Sophodra[1]
A weasel doing a visceral eversion
Weasels in this universe are very different from those in ours. While little is currently explained about them, we do know for certain that they possess unique abilities, such as "visceral eversions." This means they can open up and their organs will start to flail around. It is also explained by Gregorsa that the weasels in our world could not survive one.[2] It's explained that weasels exhibit this behavior when encountering a bunch of chickens in one place.