The effect of caste, mass and colony identity on rescue priorities in the red imported fire ant

Rescue behavior is observed across the animal kingdom. For example, many ant species engage in rescue activities. This study used experimental approaches to understand how rescuers prioritized rescue targets in the fire ant Solenopsis invicta . This research also investigated the cues that S. invicta used to locate rescue targets. We found that rescue teams likely used chemical signals to locate larval rescue targets. Reproductive larvae were preferentially rescued over worker larvae in simple choice trials; however, caches of multiple worker larvae were given equal priority during rescue compared to single reproductive larvae. Non‐nestmate reproductive larvae were rescued at the same frequency as nestmate reproductive larvae. Our results provide information on how ants locate distressed conspecifics, supporting the use of chemical signalling. Our study also offers insight into rescue priority, belying expectations of kin and reproductive prioritization by demonstrating that mass can override caste preferences. Overall, this study provides evidence that olfactory cues contribute to the coordination of rescue behaviour and suggests that large groups of workers may actually hold equal value to a eusocial insect colony as a single reproductive.