Abstract: A chemical barrier effective to irritate and repel molluscs contains an active ingredient formed of fatty acid salts of monocarboxylic acids having chain lengths ranging from 8 to 14 carbon atoms, coconut fatty acid, palm kernel fatty acid, and mixtures thereof. The barrier may be in the form of a solid or a gel-like material that is able to harden to a solid. A solid barrier may also be formed by providing a solid substrate coated with the active ingredient barrier composition.

Abstract: An effective, readily ingested molluscicidal bait poison includes an inert mollusc bait and two active ingredient precursors. These precursors are edible and non-toxic to terrestrial molluscs when consumed alone. However, the composition which includes the two precursors is fatally toxic to terrestrial molluscs. One precursor is a simple iron compound, while the other precursor is selected from edetic acid, its hydroxyethyl derivatives and salts of these acids. In another embodiment a single active ingredient may replace the two precursors. This active ingredient may include ferric edetate and the ferric hydroxyethyl derivative of edetic acid.