Individual Ants Do Not Show Activity-Rest Rhythms in Nest Conditions

Abstract

Circadian rhythms, which respond to the day-night cycle on the earth, arise from the endogenous timekeeping system within organisms, called the “biological clock.” For accurate circadian rhythms, daily fluctuations in light and temperature are considered one of the important time cues. In social insects, both abiotic and biotic factors (i.e., social interactions) play a significant role in activity-rest rhythm regulation. However, it is challenging to monitor individual activity-rest rhythms in a colony because of the large group size and small body size. Therefore, it is unclear whether individuals in a colony exhibit activity-rest rhythms and how social interactions regulate their activity-rest rhythms in the colony. This study developed an image-based tracking system using 2D barcodes for Diacamma cf. indicum from Japan (a monomorphic ant) and measured the locomotor activities of all colony members under laboratory colony conditions. We also investigated the effect of broods on activity-rest rhythms by removing all broods under colony conditions. Activity-rest rhythms appeared only in isolated ants, not under colony conditions. In addition, workers showed arrhythmic activities after brood removal. These results suggested that a mixture of social interactions, and not light and temperature, induces the loss of activity-rest rhythms. These results contribute to the knowledge of a diverse pattern of circadian activity rhythms in social insects.

Hijacking time: How Ophiocordyceps fungi could be using ant host clocks to manipulate behavior

“…In addition, individuals within the same colony can display vastly different daily rhythms depending on their age and worker ant caste. [81][82][83][84][85][86][87] Ant colonies often have a complex social organization in which the division of labour is decentralized, and an individual's caste identity is tightly linked to their daily activities.…”

“…In addition, individuals within the same colony can display vastly different daily rhythms depending on their age and worker ant caste. 81 , 82 , 83 , 84 , 85 , 86 , 87 Ant colonies often have a complex social organization in which the division of labour is decentralized, and an individual's caste identity is tightly linked to their daily activities. Generally, the older ants that leave the nest to forage for food (i.e., forager caste) do so with a distinct daily timing, while their younger sisters remain inside to take care of the brood (i.e., nurse caste) with an around the clock activity.…”

Synchronization of online social rhythms via avatar communications

“…Hence, online communication data enables us to observe global patterns of online social rhythms in online social networks.Several studies have been conducted on the macroscopic behavior of circadian rhythms due to social interactions (social synchronization) in nonhuman organisms, e.g. ants [18], fruit flies [19], honey bees [20], and shorebirds [21]. These macroscopic behaviors describe population strategies such as role allotment and social coordination in the population.Human communication dynamics are typically modeled as temporal networks, e.g.…”

The build-up of dominance hierarchies in eusocial insects

“…cf. indicum from Japan [21,22], which has a well-documented colony life cycle [23]. This species has long been reported as ‘ Diacamma sp.…”