Volus are short aliens which possesses a high-pressure greenhouse atmosphere able to support an ammonia-based biochemistry. As a result, the volus must wear pressure suits and breathers when dealing with other species. They hail from Irune which features an ammonia-based ecology and a gravitational field 1.5 times that of Earth, as well as a high-pressure atmosphere. This is reflected in the physiology of the volus themselves which are unable to survive unprotected in an atmosphere more suitable to humans and other carbon-based lifeforms. Traditional nitrogen/oxygen air mixtures are poisonous to them, and in the low pressure atmospheres tolerable to most species, their flesh will actually split open. Volus have cloacae, a trait they share with the salarians. Because they are not as physically adept as most species they make their influence felt through trade and commerce.