Monomorium subopacum is a polygynous ant species with a colony size of 100,000 workers. They have a fast development speed and the queen measures 5-6 mm while the workers measure 2-3 mm. They are brown in color and their diet consists of food insects, fruit, vegetables, and syrup. They require humidity levels of 30-50% in the arena and 50-70% in the nest, with a temperature range of 24-30°C.