Myomancy

1855 Elihu Rich in Smedley et al. Occult Sci. Myomancy was a method of divination by rats and mice, and is supposed to be alluded to in Isaiah lxvi. 17. Their peculiar cries, or some marked devastation committed by them, was taken for a prognostic of evil.

Pliny has a chapter on myomancy, or soothsaying by means of rats and mince, (Nat. Hist., lib. ix. c. 57).

1903 Daniels & Stevans Encyc. Occult Sci. Myomancy - Made use of the sounds and damage done by rats. The great Dictator Fabius Maximus renounced his throne when warned by the squeal of a mouse and Cassius Flaminius threw up his command of cavalry.

Myomancy. Divination by mice or rats, for instance, rats leaving a sinking ship.