Avicenna also says that hot imposthumes are formed from choler373 and that there is thin choler, thinner choler, and very thin choler. From thin choler,374 the imposthume called formica corrosiva is formed; from thinner choler, that called formica miliaris, the which is more in the flesh than in the skin, and is like a big ant. From very thin choler is formed the imposthume called formica deambulativa.