Unable to roll into a ball. Adult females reach a length of 15 mm, while adult males reach a length of 8 mm. Specimens were observed sitting on the substrate, on top of rocks or upside down under ledges. Occasionally they swim erratically towards the surface of the water and then would return to the substrate. Females with brood pouches or plates have never been found.
Ovaries frequently contain poorly developed eggs and males often have sperm in their sperm ducts.
Females outnumber males by 5 to 1. Bahalana geracei is not gregarious - though cannibalism does occur. Feeding behavior is unpredictable and in the natural habitat, B. geracei probably preys or scavenges on a large variety of aquatic and terrestrial animals. The family Cirolanidae is considered the most primitive of the families of the suborder Flabellifera. Bowman, T. 1987.