The Srivani believe that experimentation on other species is an acceptable method of investigating their own physiology, and justify the inevitable harm caused by citing the number of Srivani lives saved as a result.
Their normal method of experimentation involves using a phase variance of 0.15 to render themselves, their ships and their devices both invisible and intangible. They then attach to the hull of a passing ship and spend several weeks carrying out experiments on the crew. These experiments range from changes in body chemistry to complex DNA manipulation carried out by phased tags, attached to a host's DNA. They do not usually go out of their way to kill a test subject, but consider "minimal fatalities" perfectly acceptable.
In 2374, a group of Srivani used the USS Voyager as a testing ground. The experiments included adjusting the DNA of Chakotay to make him prematurely age and stimulating the dormant Mylean DNA in Neelix, causing him to express the DNA handed down from his Mylean great-grandfather. They also forced Captain Janeway to become increasingly erratic by increasing her dopamine levels.
They were discovered by Seven of Nine and The Doctor who revealed them to the rest of the crew. Since their technology could not be defeated, Janeway flew Voyager at a nearby binary pulsar, almost destroying the ship. The Srivani, realizing that they could be killed, retreated, losing one ship in the process. (VOY: "Scientific Method")
- See Unnamed Srivani