Her research looks at the evolution of insectsocial behaviour and she has studied insect species along a continuum of sociality. She showed that insects can have simple sociality based on behaviour rather than physical characteristic of a caste, and that in these simple societies individuals can change caste from worker to queen, which is not possible in complex insect societies such as honeybees. Sumner made the first use of RFID tags in field research, finding that the movement of paper wasp queens away from their home nests was much higher than expected On more complex insect societies Sumner did some of the first research on the genetic relatedness of bumblebee colonies, showing that sister queens emerging from the same colony travel far apart from each other to establish their new colonies. Sumner has also looked at the effect of social insectpopulations on their environments such as the impact of Argentine ants on seed dispersal. She has also worked on ants, looking at a parasitic ant species which evolved from and parasitises on a leaf-cutter species in Panama, she found that queens of the parasite species only mate with a single male, compared to the host leaf-cutter queens which mate with multiple males. Sumner is an advocate of the ecosystem services of social wasps saying that "wasps are useful and they are essential" and that social wasps can be predators that can help control populations of pest insects. Sumner's lab are researching how social wasps might communicate within their colony about where resources are, perhaps like honey bees do the waggle dance. In 2019 she published a Proceedings of the Royal Society B article on showing how social paper wasps can be successful predators of two economically important pests the sugarcane borer and the fall armyworm. Her research on public attitudes to bees and wasps showed that the benefits of bees are widely understood but those of wasps are not, which is also reflected in the amount of scientific research into the two groups, with wasps being underresearched compared to bees. Sumner cofounded the citizen science initiative The Big Wasp Survey in 2017 with Professor Adam Hart to raise awareness of the role and diversity of social wasp species in the UK and to compare the accuracy of citizen science data with long-term biological recording data.
Public activities
With Dr Nathalie Pettorelli of the Zoological Society of London, Sumner cofounded Soapbox Science in 2011, a platform that promotes women working in science. Sumner has taken part in Pint of Scienceevents in 2015, 2018, and 2019 and has talked at the Cheltenham Science Festival in 2016. In 2019 it was announced that Sumner would write a popular science book titled Endless Forms on wasps to be published by William Collins. With the FoAM Kernow lab in Falmouth, Sumner helped create an online game #wasplove for people to create their own wasp societies. Sumner will be an invited speaker at the EntoSci event in 2020 talking about her career to 14 to 18 year olds.
