Easton’s Bible Dictionary
Flea: David at the cave of Adullam thus addressed his persecutor Saul (1 Samuel 24:14): "After whom is the king of Israel come out? after whom dost thou pursue? after a dead dog, after a flea?" He thus speaks of himself as the poor, contemptible object of the monarch's pursuit, a "worthy object truly for an expedition of the king of Israel with his picked troops!" This insect is in Eastern language the popular emblem of insignificance. In 1 Samuel 26:20 the LXX. read "come out to seek my life" instead of "to seek a flea."