A method for inhibiting hatching of an ectoparasite egg, the method comprisingexposing the ectoparasite egg to at least one metal chelating agent and/ormetalloprotease inhibitor, wherein the metal chelating agent is a compoundcomprising at least two heteroatoms able to simultaneously coordinate with ametal ion, at least one of the two heteroatoms being selected from nitrogen,sulfur, oxygen and phosphorus, wherein the compound comprises at least onecarbocyclic ring substituted with at least one heteroatom and/or with asubstituent containing at least one heteroatom, or the compound comprises atleast one heterocyclic ring containing at least one heteroatom, wherein saidheterocyclic ring is optionally substituted with at least one heteroatomand/or with a substituent containing at least one heteroatom is provided.Methods of treating ectoparasite infestations and compositions for use in suchmethods are also provided.
