Injury-dependent wound care behavior in the desert ant Cataglyphis nodus

Abstract

Ants often face injuries during foraging, or interspecific competition, elevating infection risk and mortality among the wounded. To avoid this, ants engage in wound care on injured nestmates as a form of social immunity. In this study, we show that Cataglyphis nodus desert ants perform differentiated wound care behavior, depending on wound location and state. Leg-injured ants received significantly more wound care than antenna-injured ants. However, leg wounds with induced infections received barely any wound care from nestmates, leading to similar levels of mortality in isolation and inside the nest. Instead, such leg-infected ants are expelled from the nest, emphasizing the care-kill dichotomy in social immunity. Infections of antennal wounds showed no change in the level of wound care, nor increased mortality. Our results suggest that the level of wound care in ants can be flexibly adjusted to the perceived mortality risk of injuries. Leg injuries pose a greater risk of infection and mortality compared to antennal injuries, likely because of the larger wound area and increased vascular circulation, necessitating intensive prophylactic care to prevent infection. This study is the first to show wound care in Cataglyphis ants despite their short lifespan and offers significant insights into social immunity mechanisms.