LOW-COST MULTI-SENSOR PLATFORM FOR MONITORING INSECT BEHAVIORAL RESPONSES TO ENVIRONMENTAL CHANGE: A CASE STUDY IN ANTS

Abstract

Insect foraging behaviour is influenced by various environmental factors; however, continuous monitoring under natural conditions remains technically and financially challenging. In this study, we present a cost-effective, autonomous multi-sensor monitoring system developed to investigate the foraging behaviour of a ground dwelling ant species in relation to temperature, humidity, and light intensity. Leveraging a low-cost ESP32 microcontroller and a MATLAB-based optical flow computer vision algorithm, the system enables continuous monitoring and analysis of ant activity (ingress and egress). A comprehensive dataset was collected every 15 minutes from 23 to 29 August 2024, including environmental parameters (temperature, relative humidity, and light intensity) and corresponding ant ingress and egress counts. During the observation period, a 5-minute video feed for each time interval of 15 minutes was captured. This, paired with the environmental parameter logging system, captured data over a total duration of 168 hours (7 days), resulting in 672 discrete 15-minute intervals. Nearly 709 Carpenter ants (Family Formicidae) were observed moving either in or out of the monitored mound per 5 minutes of each interval. Distinct nocturnal patterns were observed, with peak foraging activity between 0000 and 0600 hours, and reduced activity during the daytime. The multivariate regression analysis revealed that ant activity was significantly associated with the tested parameters (p = 0.009; R² = 0.216), where temperature (p = 0.07) and humidity (p < 0.001) were found to be significantly influencing the ant activity; however, the adopted model only moderately supports these variables due to the limited number of data points. This case study reports baseline information on affordable automated systems, which can be used in behavioural ecology. Further, the findings enhance the understanding of the environmental factors influencing ant foraging and suggest a methodological framework applicable to other small-bodied terrestrial invertebrates.