Feceruntque ita; et extendit Aaron manum virgam tenens percussitque pulverem terræ. Et facti sunt scinifes in hominibus et in iumentis; omnis pulvis terræ versus est in scinifes per totam terram Aegypti.

English Translation

And they did so. And Aaron stretched forth his hand, holding the rod; and he struck the dust of the earth, and there came sciniphs on men and on beasts: all the dust of the earth was turned into sciniphs through all the land of Egypt

.A sciniph is an archaic word for ‘gnat’. Hmm. Useful to know.