To transport oxygen like every other animals.
Yes, snails have blood in their bodies. It is called hemolymph and serves a similar function to blood in other animals.
snails do need other snails around them to be happy because they have remarkable senses and brains.
The ancient Romans fattened up snails before they were killed by keeping them in a bowl of blood. The snails drank the blood until they were too fat to fit in their shells. The ancient Romans considered that the snails' blood diet made them taste nice. They sometimes, in place of blood, fed snails on milk before eating them.
snails
They have hemolymph,which corresponds to blood.
Snails are nocturnal, so are more active in the dark, but do not need to be in the dark.
A blood worm eats fresh water snails and not much else
no
yes
water
Regeneration
what are you doing with lettuce and snails? and no they will be fine