We thank David General, Palawan State University, and Andreas Schulz, Leverkusen, for the help with collecting the ants and for the valuable comments on the manuscript. The study was funded by the Deutsche Forschungsgemeinschaft DFG (He 1623/22).

Ethical standards

The experiments of the study comply with the current laws of the country in which they were performed.

Conflict of interest

The authors declare that they have no conflict of interest.