Weaknesses of this activity may cause water pollution if water flows or a snail in a place where water pressure because of the snail and live in the waters, and there is mud.
The weakness of this activity may cause water pollution if discharged Periwinkle in water or where water flows Labour Periwinkle because residents were living in stagnant water and mud dry down.
The weakness of this activity may cause for aquatic snails in the water flow, or if the place less water flow force because snails live and live in the source of stagnant water and mud.