The female, male and larva of a new species of ScutacarusGros, 1845 (Acari: Heterostigmatina: Scutacaridae) and male and larva of Petalomium megasolenidiatum Silva, Khaustov & Oliveira, 2018a (Neopygmephoridae) are described. These mites were found associated with Camponotus cingulatusMayr, 1862 (Hymenoptera: Formicidae) in the state of Bahia, Northeastern Brazil. Biological aspects of the mites living in the ant's nest are discussed.