“What did the Red Wrigglers do to deserve such a derogatory second name (for non Latin scholars it translates as “stinking”)? Mine don’t smell. Do any of them? Regards” ~ Patrick Kenealy
Foetida does indeed translate to ‘stinking’.
This is also where the english word ‘Fetid’ comes from.
Now why do they have this name?
You are half right that they don’t smell. Normally these worms indeed have no foul smell at all. However once they feel they are under attack, they have two methods of defending themselves.
They will wriggle frantically.
Sometimes I call this the worm dance.
But by wriggling frantically it deters attacking birds and minimizes chance of them being picked up and eaten.
The second way they defend themselves is by secreting a brownish yellow liquid. This is the liquid which smells and hence their name!
Interestingly some other worms do the same such as the Eisenia Andreii, but they don’t get the foul name!