Slugs can actually kill you if they infect you with a parasite known as a lungworm.
The slug carries a parasitic nematode (Angiostrongylus cantonensis) known as the rat lungworm which can infect humans if the slug bites the human.
Slugs can bite humans if they wanted too.
However as long as you don't touch or pick up the slug then it will mostly stay away from you and not try to bite you.
It's not recommended to pick up a slug unless you're wearing some gloves to prevent the potential of getting bitten although getting bitten by the slug is very rare.
Slugs are mostly attracted to things such as moisture, water, warmth, plant leaves, fruit plants etc.
Even having pet food such as cat food, dog food or even food crumbs laying out can attract slugs to your house.
Copper pennies that were mostly made of copper would actually repel slugs.
But now pennies are made mostly of Zinc and not all copper so they are not as good at repelling slugs as they used to be.
You can use regular copper to repel slugs as the slugs will not cross the path of copper as they hate copper.
A slug does not feel pain the same way we humans do but from research the slug likely feels a tingling sensation instead of actual pain.
If a slug is chopped up, cut, stepped on etc they won't feel the pain like us humans would feel the pain.
Slugs don't have a cerebral cortex which is the part of the brain responsible for the conscious perception of pain.
Slugs usually come into your house at night for warmth, shade or even food etc.
The Yellow Cellar slug mostly eats mold and algae but can also be found eating leftovers, pet food and compost.
Slugs including the yellow cellar slug also is attracted to dark damp refuges such as vents and drains so make sure to remove any standing water and get rid of dampness around your house.
You can use salt to kill slugs when they come into your house.
Just pour some regular table salt onto the slugs body and the salt will dry out the slugs body and dehydrate the slug which causes the slug to do.
The salt slowly kills the slugs and it's a safe and natural way to kill slugs.
Putting some Epsom Salt around areas where the slugs come inside can also help repel the slugs.
Also check for where the slugs are coming in and seal any holes or entry ways for the slugs so they cannot get in.