Many animal species carry diseases which can spill over to humans, with severe health and economic consequences. Therefore, there is considerable interest in understanding how these diseases are maintained in wild animal populations. Like humans, many animals do not mix randomly with others, yet accurately quantifying contact behaviour data is hard, even for large or observable species, and often requires substantial investment of both time and money. For small, nocturnal species such as rodents, surveying contact behaviour in the wild has been impossible. We have developed cutting edge Social Contact Network (SCoNe) loggers that weigh less than 1.5g, can be attached as a collar for up to 28 days and can log interactions between up to 70 animals at a time. We will use these to investigate contact behaviour in the multimammate mouse in Tanzania to understand virus transmission. These mice transmit diseases such as Lassa fever and plague, and can have several litters a year of more than 20 young. As a result, they become extremely abundant, causing huge crop damage. Understanding how mice behaviour varies through population changes, and how this influences transmission will help protect crop yields and inform public health strategies, as well as answering fundamental questions about disease transmission. Due to their small size and open source design, SCoNe loggers will be easily adapted by other researchers, shedding light on behavioural interactions for a range of species.