The thing is that there is dangerous illness that is propagated by this insects.
The main source are rats poo, and then the slug eat it and leave the larva on their trails. Different varieties form this parasite affect animals and humans, but this in particular has only be described in Costa Rica and there have been cases in Central and South America. Slugs may infect also vegetables.
The risk population are toddlers ans babies, more the boys than the girls.
When they enter the human body go into the blood and then to the intestine where they develop, cutting blood access to the tissue which eventually dies and then the patient will not be able to get any nutrients.
Surgery has been necessary in some cases and at least one baby girl died from this, she eat the whole slug. Recovery can take months of hospitalization.
Symptoms include fever, diarrhea, and pain and hardness on the right side of the belly.
A study of slog population around Costa Rica showed that 50% of this animals were infected without matter the area.
So let's be careful, doctors recommend to be super clean, wash hand often and disinfect vegetables.