Entomomancy is the art of divination by the appearance of actions of insects.
From Greek entomos, an insect.
The ancient Greeks had numerous beliefs about portentious insects. Ants were meant to have presaged the death of Cimon, and, also, the great wealth of Midas was foretold by ants coming to him as a boy while asleep and dropping grains of wheat into his mouth. According to Potter, bees “were esteemed an omen of future eloquence”, and he cites the well-known story of Plato, who, as a baby in the cradle was visited by a swarm of bees which alighted on his lips, thereby predicting his gift of oratory. The praying mantis (mantis means diviner), was observed for divinatory purpose. Some of the beliefs have survived in popular folklore, such as crickets bringing good luck, and ladybirds indicating visitors.