How Do Ants Work in Shifts?

Several studies have suggested that ants might be able to divide their labor in work shifts. However, the mechanisms underlying this behaviour are still unclear.

One hypothesis is that leaf-cutting ants might be able to divide their labour. In this model, a worker leaves the nest and goes out to forage, then returns with leaves. During the night, the worker spends time with other ants that recently returned from foraging.

To test this hypothesis, we investigated the behavior of leaf-cutting ants in a controlled environment. We used a LOGITECH c920 HD Webcam connected to a surveillance software package.

We recorded videos of leaf-cutting ants carrying leaves during four different work shifts. Each work shift had a different light phase and different foraging activity. During the light phase, ants were less effective at foraging, but during the dark phase they were more efficient.

The ants were manually marked with a SHARPIE oil-based ink. They were then recorded in video for five days. The number of marked ants was compared between each work shift.

The number of marked ants was then used as a response variable. A generalized linear mixed model (GLMM) was used to test the difference between the number of ants observed in each shift.

The GLMM results showed that the number of marked ants was strongly correlated with the work shift. This is because the number of marked ants was mainly dependent on the lighting condition. During the light phase, the marked ants were more active in foraging, while in the dark phase they were less active.