[2] Although he retired the same year,[3] a new drug developed soon after his diagnosis kept the disease in check, allowing him to continue to work, despite often having to use a wheelchair due to his frailty.

Schneirla was studying the behaviour of army ants and needed an assistant to work for six months on Barro Colorado Island (BCI) in Panama, which Rettenmeyer accepted.

[2] Schneirla was interested in army ants behaviour as he thought that by studying it he could understand how it would be possible for humans to fight wars more effectively.

[5] After graduating he studied a PhD in entomology at the University of Kansas under the supervision of Charles Duncan Michener, which he completed in 1962.

Rettenmeyer says that this was his "lucky break" and during nine weeks spent on BCI he collected thousands of specimens, including 147 species of mite found living on the ants.

His work also inspired other researchers to investigate such diverse areas as avian ecology, social insect symbioses, tropical phenology and conservation biology.

[5] He was one of the first biologists to visit Monteverde Cloud Forest Reserve in Costa Rica, which is now a major center for Neotropical research.

[10] He spent his later years examining samples from 1,600 army ant colonies he had collected and in total found 45,000 mites.

[5] Scientists are continuing to study the specimens Rettenmeyer collected during his life and one researcher told the BBC that she expected that the number of associated species could potentially double once the work is completed.

[2][14] Among his accomplishments was photographing army ants mating for the first time, as well as estimating the longevity of the queen by recapturing a specimen.

It was reviewed as being extremely information rich and a "must-see for ant enthusiasts" but so full of facts it is exhausting to watch.