Table 5.
Scoring scales of observed behaviours with detailed description for Data Sets 1–3.
| Observed behaviours | Scoring scale used in Data Sets 1 and 2 | Names of behaviour used in scoring Data Sets 1 and 2 | Original scoring scale used in Data Set 3 in Krapf et al.45 | Names of behaviour used in scoring Data Set 3 | Adapted scoring scale for Data Set 3 used in this study |
|---|---|---|---|---|---|
| Killing results from lower-level behaviour. Killing reveals information on maximum determination and the superiority of one of the opponents, which both are relevant when assaying the behaviour two particular opponents engage in. Killing is absolute, in that after killing, the behaviour observation stops. | 5 | Killing | |||
| Fighting with gaster flexion is biting and trying to sting (e.g., Myrmicinae) or spraying with, e.g., acid (Formicinae) the other worker. | 4 | Fighting with gaster flexion | 7 | Fighting | 4 |
| Fighting is biting without gaster flexion. | 3 | Fighting without gaster flexion | 6 | Biting | 3 |
| Mandible threatening is opening the mandibles to display potential aggressiveness but without biting the other worker. | 2 | Mandible threatening | 5 | Mandible threatening | 2 |
| Avoiding is fleeing from the other worker, usually by walking backwards. | 1 | Avoiding | 4 | Avoiding | 1 |
| Ignoring is the lack of an interaction of workers; workers can thus be both sitting, in a distance of more than 1 mm from each other, or one or both workers can be moving. | 0 | Ignoring | 0 | Ignoring | 0 |
| Being next to each other is sitting of both workers in close proximity (1 mm at the maximum) to each other, following contact. | −1 | Being next to each other without touching | 1 | Being next to each other without touching | −1 |
| Antennation is the touching of the other worker with the antennae. During antennation, workers assess whether the other worker belongs to the same colony (nestmate) or not (non-nestmate). Furthermore, during a prolonged antennation time, information on food sources, foraging locations, orientation cues, and trail conditions, among others, might be exchanged between workers59–62, that is, antennation is meaningful also in context other than nestmate recognition. Assessing antennation is important for ant species where no information on nestmate recognition has been available and for ant species which are non-aggressive in intraspecific aggression assays but which can discriminate between nestmates and non-nestmates. | −2 | Antennation | 2 | Antennation | −2 |
| Allogrooming is the cleaning of another worker. | −3 | Allogrooming | 3 | Allogrooming and trophallaxis | −3 |
| Trophallaxis is the exchange of food or fluids between workers during which also chemical cues, growth proteins, and hormones are transferred69. | −4 | Trophallaxis |
Note: The scoring scales used in this study are based on a pilot study using worker encounters of multiple ant species (Myrmicinae, Formicinae). Various encounters were performed, and the behaviours of the workers were filmed, analysed, and categorised. See Supplementary material for a detailed description of the behaviours used and for frequency boxplots of Data Sets 1–3 (Figs. S2–S7). The scoring scale of Data Set 3 was adapted to fit the scoring scales of Data Sets 1 and 2.