Mr Slow and balance

This small shell animal I take it from 10 cm distance , they walk very very slowly... , In some cases sometime they crack it because someone hit it with rock . Do you know how they balance the garden lifecycle ? . All grass , flower root and even big mangos need this little creature. They need their saliva ( like jelly) sticky , cause it's contain huge enzyme that need to lubricate the system that can open root pore even land pore. If this small animal did not found at garden , the life cycle won't finish and seems grass specially dry it self. I prove it already 8 years till now. I never move these animal from my garden . Even I gave them with more food come from rice , waste kitchen product and others.
I never use syntetic fertiliser , so this is like organic fertiliser. Maybe in other side they can destroy your colour full flower but not at all, they only want to eat, that's the fact.