Understanding the Hygienic Behavioral Dynamics of Ants Using Multi‐State Models

ABSTRACT Understanding social immunity mechanisms in ant colonies is crucial for comprehending the evolution of defense strategies in eusocial organisms. Assuming the absence of memory‐based responses, the present study explores how prior behaviors and interactions among leaf‐cutting workers influence collective hygiene strategies in the presence of pathogens and vulnerable colony members. Markov transition models were applied to describe changes in grooming behavior over time under different treatment conditions. Significant behavioral changes were observed when the ants were exposed to an entomopathogenic fungus species in the presence of a fungus garden and a larva. A strong association between prophylactic grooming and the presence of vulnerable individuals was confirmed. Behavioral transitions and timing varied across treatments, suggesting that workers adjust responses according to environmental context. Allogrooming behavior decreased in persistence under pathogen exposure, indicating potential effects on pathogen transmission dynamics, while self‐grooming became the most persistent state. Grooming bouts became shorter but occurred more frequently, increasing total grooming effort in treatments with pathogens and vulnerable nestmates. These findings highlight the complex interplay between internal colony factors and external threats in shaping hygienic responses. Decision‐making appears to be influenced by contextual cues, emphasizing the importance of both intrinsic colony organization and environmental stressors. The use of continuous‐time Markov models (multi‐state models) enabled the quantification of behavioral sequences and revealed subtle patterns not detectable through direct observation. This study applies a continuous‐time multi‐state Markov framework to grooming sequences in ants, offering a novel, quantitative view of transition rates, persistence, and treatment effects across pathogen and social contexts. By examining how hygienic behaviors adapt to infection risk and social context, new perspectives are provided on disease resilience and the evolution of collective decision‐making in insect societies.