Odontomachus brunneus is a polygynous ant species with colony sizes of up to 500 workers. They have a medium development speed. The queens are 10-12 mm in size, while the workers are 10-11 mm. They are brown in color with golden to reddish brown legs. They feed on food insects like cockroaches and crickets, as well as sweet fruit. They require a humidity level of 50-70% in both the arena and nest. The temperature requirements are not specified.