The things that bring the spirits to Odysseus is the sacrifices of the sheep and the blood pool they offer to the dead.
Answer:
Well if I had to guess, first of all I would say that there wouldn't be any food for the hungry snakes or spiders, so usually the snakes would die, be dead, or just eat the spiders that are there ¯\_(ツ)_/¯
A call will be made by my friend to me.